JESD204B/C Link Transmit Peripheral
The Analog Devices JESD204B/C Link Transmit Peripheral implements the link layer handling of a JESD204 transmit logic device. Implements the 8B/10B based link layer defined in JESD204C standard that is similar to the link layer defined in JESD204B. This includes handling of the SYSREF and SYNC~ and controlling the link state machine accordingly as well as performing per lane scrambling and character replacement. It has been designed for interoperability with Analog Devices JESD204B DAC converter products. Implements the 64B/66B based link layer defined in the JESD204C standard. This includes handling of the SYSREF, per lane encoding of sync header, scrambling as per data multi-block CRC generation.
The type of link layer is selectable during implementation phase through the
LINK_MODE
synthesis parameter.
To form a complete JESD204 transmit logic device it has to be combined with a PHY layer and transport layer peripheral.
Features
Backwards compatibility with JESD204B;
64B/66B link layer defined in JESD204C;
Subclass 0 and Subclass 1 support;
Deterministic Latency (for Subclass 1 operation);
Runtime re-configurability through memory-mapped register interface (AXI4);
Interrupts for event notification;
Diagnostics;
Max Lanerate with 8B/10B mode: 15 Gbps;
Max Lanerate with 64B/66B mode: 32 Gbps;
Low Latency;
Independent per lane enable/disable.
Files
Name |
Description |
---|---|
Verilog source for the peripheral. |
|
TCL script to generate the Vivado IP-integrator project for the peripheral. |
Block Diagram
AXI JESD204 TX Synthesis Configuration Parameters
Name |
Description |
Default Value |
Choices/Range |
---|---|---|---|
ID |
Instance identification number. |
0 |
|
NUM_LANES |
Maximum number of lanes supported by the peripheral. |
1 |
|
NUM_LINKS |
Maximum number of links supported by the peripheral. |
1 |
|
LINK_MODE |
Decoder selection of the link layer. 1 - 8B/10B mode; 2 - 64B/66B mode. |
1 |
64B66B (2), 8B10B (1) |
ENABLE_LINK_STATS |
Enable Link Stats. |
0 |
|
DATA_PATH_WIDTH |
Data path width in bytes. Set it 4 in case of 8B/10B, 8 in case of 64B/66B. |
4 |
JESD204 TX Synthesis Configuration Parameters
Name |
Description |
Default Value |
Choices/Range |
---|---|---|---|
NUM_LANES |
Maximum number of lanes supported by the peripheral. |
1 |
|
NUM_LINKS |
Maximum number of links supported by the peripheral. |
1 |
|
NUM_OUTPUT_PIPELINE |
Num Output Pipeline. |
0 |
|
LINK_MODE |
Decoder selection of the link layer. 1 - 8B/10B mode; 2 - 64B/66B mode. |
1 |
64B66B (2), 8B10B (1) |
DATA_PATH_WIDTH |
Data path width in bytes. Set it to 4 in case of 8B/10B, 8 in case of 64B/66B. |
4 |
|
TPL_DATA_PATH_WIDTH |
Data path width in bytes towards transport layer. Must be greater or equal to |
4 |
|
ENABLE_CHAR_REPLACE |
Enable Char Replace. |
'b0 |
|
ASYNC_CLK |
Set this parameter to 1 if the link clock and the device clocks have different frequencies, or if they have the same frequency but a different source. If set, synchronizing logic and a gearbox of ratio |
1 |
|
SYSREF_IOB |
Place SYSREF in IOB. |
True |
AXI JESD204 TX Signal and Interface Pins
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
s_axi_awaddr |
AWADDR |
in [13:0] |
|
s_axi_awprot |
AWPROT |
in [2:0] |
|
s_axi_awvalid |
AWVALID |
in |
|
s_axi_awready |
AWREADY |
out |
|
s_axi_wdata |
WDATA |
in [31:0] |
|
s_axi_wstrb |
WSTRB |
in [3:0] |
|
s_axi_wvalid |
WVALID |
in |
|
s_axi_wready |
WREADY |
out |
|
s_axi_bresp |
BRESP |
out [1:0] |
|
s_axi_bvalid |
BVALID |
out |
|
s_axi_bready |
BREADY |
in |
|
s_axi_araddr |
ARADDR |
in [13:0] |
|
s_axi_arprot |
ARPROT |
in [2:0] |
|
s_axi_arvalid |
ARVALID |
in |
|
s_axi_arready |
ARREADY |
out |
|
s_axi_rdata |
RDATA |
out [31:0] |
|
s_axi_rresp |
RRESP |
out [1:0] |
|
s_axi_rvalid |
RVALID |
out |
|
s_axi_rready |
RREADY |
in |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
s_axi_aclk |
CLK |
in |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
s_axi_aresetn |
RST |
in |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
core_cfg_lanes_disable |
lanes_disable |
out [0:0] |
|
core_cfg_links_disable |
links_disable |
out [0:0] |
|
core_cfg_octets_per_multiframe |
octets_per_multiframe |
out [9:0] |
|
core_cfg_octets_per_frame |
octets_per_frame |
out [7:0] |
|
core_cfg_continuous_cgs |
continuous_cgs |
out |
|
core_cfg_continuous_ilas |
continuous_ilas |
out |
|
core_cfg_skip_ilas |
skip_ilas |
out |
|
core_cfg_mframes_per_ilas |
mframes_per_ilas |
out [7:0] |
|
core_cfg_disable_char_replacement |
disable_char_replacement |
out |
|
core_cfg_disable_scrambler |
disable_scrambler |
out |
|
device_cfg_octets_per_multiframe |
device_octets_per_multiframe |
out [9:0] |
|
device_cfg_octets_per_frame |
device_octets_per_frame |
out [7:0] |
|
device_cfg_beats_per_multiframe |
device_beats_per_multiframe |
out [7:0] |
|
device_cfg_lmfc_offset |
device_lmfc_offset |
out [7:0] |
|
device_cfg_sysref_oneshot |
device_sysref_oneshot |
out |
|
device_cfg_sysref_disable |
device_sysref_disable |
out |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
core_ilas_config_rd |
rd |
in |
|
core_ilas_config_addr |
addr |
in [1:0] |
|
core_ilas_config_data |
data |
out [31:0] |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
device_event_sysref_alignment_error |
sysref_alignment_error |
in |
|
device_event_sysref_edge |
sysref_edge |
in |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
core_status_state |
state |
in [1:0] |
|
core_status_sync |
sync |
in [0:0] |
|
status_synth_params0 |
synth_params0 |
in [31:0] |
|
status_synth_params1 |
synth_params1 |
in [31:0] |
|
status_synth_params2 |
synth_params2 |
in [31:0] |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
core_ctrl_manual_sync_request |
manual_sync_request |
out |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
irq |
INTERRUPT |
out |
Physical Port |
Direction |
Dependency |
Description |
---|---|---|---|
core_clk |
in |
Bus |
|
core_reset_ext |
in |
||
core_reset |
out |
Bus |
|
device_clk |
in |
Device clock for the JESD204 interface. Its frequency must be link clock * |
|
device_reset |
out |
Reset active high synchronous with the Device clock. |
JESD204 TX Signal and Interface Pins
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
tx_valid |
TVALID |
in |
|
tx_ready |
TREADY |
out |
|
tx_data |
TDATA |
in [31:0] |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
cfg_lanes_disable |
lanes_disable |
in [0:0] |
|
cfg_links_disable |
links_disable |
in [0:0] |
|
cfg_octets_per_multiframe |
octets_per_multiframe |
in [9:0] |
|
cfg_octets_per_frame |
octets_per_frame |
in [7:0] |
|
cfg_continuous_cgs |
continuous_cgs |
in |
|
cfg_continuous_ilas |
continuous_ilas |
in |
|
cfg_skip_ilas |
skip_ilas |
in |
|
cfg_mframes_per_ilas |
mframes_per_ilas |
in [7:0] |
|
cfg_disable_char_replacement |
disable_char_replacement |
in |
|
cfg_disable_scrambler |
disable_scrambler |
in |
|
device_cfg_octets_per_multiframe |
device_octets_per_multiframe |
in [9:0] |
|
device_cfg_octets_per_frame |
device_octets_per_frame |
in [7:0] |
|
device_cfg_beats_per_multiframe |
device_beats_per_multiframe |
in [7:0] |
|
device_cfg_lmfc_offset |
device_lmfc_offset |
in [7:0] |
|
device_cfg_sysref_oneshot |
device_sysref_oneshot |
in |
|
device_cfg_sysref_disable |
device_sysref_disable |
in |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
ilas_config_rd |
rd |
out |
|
ilas_config_addr |
addr |
out [1:0] |
|
ilas_config_data |
data |
in [31:0] |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
device_event_sysref_alignment_error |
sysref_alignment_error |
out |
|
device_event_sysref_edge |
sysref_edge |
out |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
status_state |
state |
out [1:0] |
|
status_sync |
sync |
out [0:0] |
|
status_synth_params0 |
synth_params0 |
out [31:0] |
|
status_synth_params1 |
synth_params1 |
out [31:0] |
|
status_synth_params2 |
synth_params2 |
out [31:0] |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
ctrl_manual_sync_request |
manual_sync_request |
in |
Physical Port |
Logical Port |
Direction |
Dependency |
---|---|---|---|
phy_data |
txdata |
out [31:0] |
|
phy_charisk |
txcharisk |
out [3:0] |
|
phy_header |
txheader |
out [1:0] |
Physical Port |
Direction |
Dependency |
Description |
---|---|---|---|
clk |
in |
Link clock for the JESD204 interface. Must be line clock/40 for correct operation in 8B/10B mode, line clock/66 in 64B/66B mode. Bus |
|
reset |
in |
Reset active high synchronous with the Link clock. Bus |
|
device_clk |
in |
Bus |
|
device_reset |
in |
Bus |
|
sysref |
in |
JESD204 SYSREF signal. |
|
lmfc_edge |
out |
||
lmfc_clk |
out |
||
sync |
in [0:0] |
LINK_MODE = 1 |
sync[m-1:0] is JESD204B SYNC~ (or SYNC_N) signal, available in 8B/10B mode. ( |
tx_eof |
out [3:0] |
||
tx_sof |
out [3:0] |
||
tx_somf |
out [3:0] |
||
tx_eomf |
out [3:0] |
Register Map
DWORD |
BYTE |
Reg Name |
Description |
|||
---|---|---|---|---|---|---|
BITS |
Field Name |
Type |
Default Value |
Description |
||
0x0 |
0x0 |
VERSION |
Version of the peripheral. Follows semantic versioning. Current version 1.03.a. |
|||
[31:16] |
VERSION_MAJOR |
RO |
0x0001 |
|||
[15:8] |
VERSION_MINOR |
RO |
0x03 |
|||
[7:0] |
VERSION_PATCH |
RO |
0x61 |
|||
0x1 |
0x4 |
PERIPHERAL_ID |
||||
[31:0] |
PERIPHERAL_ID |
RO |
Value of the ID configuration parameter. |
|||
0x2 |
0x8 |
SCRATCH |
||||
[31:0] |
SCRATCH |
RW |
0x00000000 |
Scratch register useful for debug. |
||
0x3 |
0xc |
IDENTIFICATION |
||||
[31:0] |
IDENTIFICATION |
RO |
0x32303454 |
Peripheral identification (‘2’, ‘0’, ‘4’, ‘T’). |
||
0x4 |
0x10 |
SYNTH_NUM_LANES |
||||
[31:0] |
SYNTH_NUM_LANES |
RO |
Number of supported lanes. |
|||
0x5 |
0x14 |
SYNTH_DATA_PATH_WIDTH |
||||
[31:16] |
RESERVED |
RO |
0x0000 |
|||
[15:8] |
TPL_DATA_PATH_WIDTH |
RO |
0x02 |
Data path width in octets at Transport Layer interface. Available starting from version 1.06.a; |
||
[7:0] |
SYNTH_DATA_PATH_WIDTH |
RO |
0x02 |
Log2 of internal data path width in octets. Represents the datapath width towards the physical interface. |
||
0x6 |
0x18 |
SYNTH_1 |
Core description register. |
|||
[31:19] |
RESERVED |
RO |
0x0000 |
|||
[18] |
ENABLE_CHAR_REPLACE |
RO |
0x0 |
This bit reflects the presence of character replacement insertion logic for cases when scrambling is disabled. Available starting from version 1.06.a; |
||
[12] |
ASYNC_CLK |
RO |
ASYNC_CLK |
This bit is set if link clock and device clock are connected to different sources. This is useful for supporting modes where datapath width is not integer multiple of F. Available starting from version 1.06.a; |
||
[9:8] |
ENCODER |
RO |
Encoder presence: 01 - 8B10B encoder \ 10 - 64B66B encoder |
|||
[7:0] |
NUM_LINKS |
RO |
Maximum supported links. Valid for 8B/10B link. |
|||
0x20 |
0x80 |
IRQ_ENABLE |
||||
[31:0] |
IRQ_ENABLE |
RW |
0x00000000 |
Interrupt enable. |
||
0x21 |
0x84 |
IRQ_PENDING |
||||
[31:0] |
IRQ_PENDING |
RW1CV |
0x00000000 |
Pending and enabled interrupts. |
||
0x22 |
0x88 |
IRQ_SOURCE |
||||
[31:0] |
IRQ_SOURCE |
RW1CV |
0x00000000 |
Pending interrupts. |
||
0x30 |
0xc0 |
LINK_DISABLE |
JESD204B link disable. |
|||
[31:1] |
RESERVED |
RO |
0x00000000 |
|||
[0] |
LINK_DISABLE |
RW |
0x1 |
0 = Enable link, 1 = Disable link. |
||
0x31 |
0xc4 |
LINK_STATE |
JESD204B link state. |
|||
[31:2] |
RESERVED |
RO |
0x00000000 |
|||
[1] |
EXTERNAL_RESET |
RO |
0 = External reset de-asserted, 1 = External reset asserted. |
|||
[0] |
LINK_STATE |
RO |
0x1 |
0 = Link enabled, 1 = Link disabled. |
||
0x32 |
0xc8 |
LINK_CLK_FREQ |
||||
[31:0] |
LINK_CLK_FREQ |
ROV |
Ratio of the link_clk frequency relative to the s_axi_aclk. Format is 16.16. |
|||
0x33 |
0xcc |
DEVICE_CLK_FREQ |
||||
[20:0] |
DEVICE_CLK_FREQ |
ROV |
Ratio of the device_clk frequency relative to the s_axi_aclk. Format is 16.16. Available starting from version 1.06.a; |
|||
0x40 |
0x100 |
SYSREF_CONF |
SYSREF configuration |
|||
[31:2] |
RESERVED |
RO |
0x00000000 |
|||
[1] |
SYSREF_ONESHOT |
RW |
0x0 |
In oneshot mode only the first occurrence of the SYSREF signal is used for alignment. |
||
[0] |
SYSREF_DISABLE |
RW |
0x0 |
Enable/Disable SYSREF handling. |
||
0x41 |
0x104 |
SYSREF_LMFC_OFFSET |
SYSREF LMFC offset |
|||
[31:10] |
RESERVED |
RO |
0x000000 |
|||
[9:0] |
SYSREF_LMFC_OFFSET |
RW |
0x000 |
Offset between SYSREF event and internal LMFC event in octets. |
||
0x42 |
0x108 |
SYSREF_STATUS |
SYSREF status |
|||
[31:2] |
RESERVED |
RO |
0x00000000 |
|||
[1] |
SYSREF_ALIGNMENT_ERROR |
RW1CV |
0x0 |
Indicates that an external SYSREF event has been observed that was unaligned to a previously observed event. |
||
[0] |
SYSREF_DETECTED |
RW1CV |
0x0 |
Indicates that an external SYSREF event has been observed. |
||
0x80 |
0x200 |
LANES_DISABLE |
Enabled/Disabled lanes. |
|||
[n] |
LANE_DISABLEn |
RW |
0x0 |
Enable/Disable n-th lane (0 = enabled, 1 = disabled). Where n is from 0 to 31. |
||
0x84 |
0x210 |
LINK_CONF0 |
JESD204B link configuration. |
|||
[31:19] |
RESERVED |
RO |
0x0000 |
|||
[18:16] |
OCTETS_PER_FRAME |
RW |
0x0 |
Number of octets per frame - 1 (F). |
||
[15:10] |
RESERVED |
RO |
0x00 |
|||
[9:0] |
OCTETS_PER_MULTIFRAME |
RW |
0x003 |
Number of octets per multi-frame - 1 (K x F). In 64B/66B mode represents the number of octets per extended multiblock. |
||
0x85 |
0x214 |
LINK_CONF1 |
JESD204B link configuration. |
|||
[31:2] |
RESERVED |
RO |
0x00000000 |
|||
[1] |
CHAR_REPLACEMENT_DISABLE |
RW |
0x0 |
Enable/Disable user data alignment character replacement (0 = enabled, 1 = disabled). Valid for 8B/10B link. |
||
[0] |
SCRAMBLER_DISABLE |
RW |
0x0 |
Enable/Disable user data descrambling (0 = enabled, 1 = disabled). |
||
0x86 |
0x218 |
MULTI_LINK_DISABLE |
Enable/Disable links in case of a multi-link architecture. Valid for 8B/10B link. |
|||
[n] |
LINK_DISABLEn |
RW |
0x0 |
Enable/Disable n-th link (0 = enabled, 1 = disabled). Where n is from 0 to 31. |
||
0x87 |
0x21c |
LINK_CONF4 |
JESD204B link configuration. |
|||
[31:8] |
RESERVED |
RO |
0x000000 |
|||
[7:0] |
TPL_BEATS_PER_MULTIFRAME |
RW |
0x00 |
Number of beats per multi-frame - 1 (K x F / TPL_DATA_PATH_WIDTH) at interface to Transport Layer. In 64B/66B mode represents the number of octets per extended multiblock. Available starting from version 1.06.a; |
||
0x90 |
0x240 |
LINK_CONF2 |
JESD204B link configuration. Valid for 8B/10B link. |
|||
[31:3] |
RESERVED |
RO |
0x00000000 |
|||
[2] |
SKIP_ILAS |
RW |
0x0 |
Skip ILAS sequence during link startup. |
||
[1] |
CONTINUOUS_ILAS |
RW |
0x0 |
Continuously transmit ILAS sequence. |
||
[0] |
CONTINUOUS_CGS |
RW |
0x0 |
Continuously transmit CGS sequence. |
||
0x91 |
0x244 |
LINK_CONF3 |
JESD204B link configuration. Valid for 8B/10B link. |
|||
[31:8] |
RESERVED |
RO |
0x000000 |
|||
[7:0] |
MFRAMES_PER_ILAS |
RW |
0x03 |
Number of multi-frames in the ILAS sequence - 1. |
||
0x92 |
0x248 |
MANUAL_SYNC_REQUEST |
Manual synchronization request. Valid for 8B/10B link. |
|||
[31:1] |
RESERVED |
RO |
0x00000000 |
|||
[0] |
MANUAL_SYNC_REQUEST |
W1S |
0x0 |
Trigger manual synchronization request. |
||
0xa0 |
0x280 |
LINK_STATUS |
JESD204B link status. |
|||
[31:12] |
RESERVED |
RO |
0x00000 |
|||
[11:4] |
STATUS_SYNC |
ROV |
Raw state of the external SYNC~ signals. Valid for 8B/10B link. |
|||
[3:2] |
RESERVED |
RO |
0x0 |
|||
[1:0] |
STATUS_STATE |
ROV |
0x0 |
State of the 8B/10B link state machine. (0 = WAIT, 1 = CGS, 2 = ILAS, 3 = DATA); State of the 64B/66B link state machine. (0 = RESET, 3 = DATA) |
||
0xc4 + 0x8*n |
0x310 + 0x20*n |
LANEn_ILAS0 |
ILAS config data for the n-th lane. Valid for 8B/10B link. Where n is from 0 to 31. |
|||
[31:28] |
RESERVED |
RO |
0x0 |
|||
[27:24] |
BID |
RW |
0x0 |
BID (Bank ID) field of the ILAS config sequence. |
||
[23:16] |
DID |
RW |
0x00 |
DID (Device ID) field of the ILAS config sequence. |
||
[15:0] |
RESERVED |
RO |
0x0000 |
|||
0xc5 + 0x8*n |
0x314 + 0x20*n |
LANEn_ILAS1 |
ILAS config data for the n-th lane. Valid for 8B/10B link. Where n is from 0 to 31. |
|||
[31:29] |
RESERVED |
RO |
0x0 |
|||
[28:24] |
K |
RW |
0x00 |
K (Frames per multi-frame) field of the ILAS config sequence - 1. |
||
[23:16] |
F |
RW |
0x00 |
F (Octets per frame) field of the ILAS config sequence - 1. |
||
[15] |
SCR |
RW |
0x0 |
SCR (Scrambling enabled) field of the ILAS config sequence. |
||
[14:13] |
RESERVED |
RO |
0x0 |
|||
[12:8] |
L |
RW |
0x00 |
L (Number of lanes) field of the ILAS config sequence - 1. |
||
[7:5] |
RESERVED |
RO |
0x0 |
|||
[4:0] |
LID |
RW |
0x00 |
LID (Lane ID) field of the ILAS config sequence. |
||
0xc6 + 0x8*n |
0x318 + 0x20*n |
LANEn_ILAS2 |
ILAS config data for the n-th lane. Valid for 8B/10B link. Where n is from 0 to 31. |
|||
[31:29] |
JESDV |
RW |
0x0 |
JESDV (JESD204 version) field of the ILAS config sequence. |
||
[28:24] |
S |
RW |
0x00 |
S (Samples per frame) field of the ILAS config sequence - 1. |
||
[23:21] |
SUBCLASSV |
RW |
0x0 |
SUBCLASSV (JESD204B subclass) field of the ILAS config sequence. |
||
[20:16] |
NP |
RW |
0x00 |
N’ (Total number of bits per sample) field of the ILAS config sequence - 1. |
||
[15:14] |
CS |
RW |
0x0 |
CS (Control bits per sample) field of the ILAS config sequence. |
||
[13] |
RESERVED |
RO |
0x0 |
|||
[12:8] |
N |
RW |
0x00 |
N (Converter resolution) field of the ILAS config sequence - 1. |
||
[7:0] |
M |
RW |
0x00 |
M (Number of converters) field of the ILAS config sequence - 1. |
||
0xc7 + 0x8*n |
0x31c + 0x20*n |
LANEn_ILAS3 |
ILAS config data for the n-th lane. Valid for 8B/10B link. Where n is from 0 to 31. |
|||
[31:24] |
FCHK |
RW |
0x00 |
FCHK (Checksum) field of the ILAS config sequence. |
||
[23:8] |
RESERVED |
RO |
0x0000 |
|||
[7] |
HD |
RW |
0x0 |
HD (High-density) field of the ILAS config sequence. |
||
[6:5] |
RESERVED |
RO |
0x0 |
|||
[4:0] |
CF |
RO |
0x00 |
CF (control words per frame) field of the ILAS config sequence |
Theory of Operation
The JESD204B/C transmit peripheral consists of two main components. The register
map and the link processor. Both components are fully asynchronous and are
clocked by independent clocks. The register map is in the s_axi_aclk
clock
domain, while the link processor is in the clk
and device_clk
clock
domain.
The register map is used to configure the operational parameters of the link processor as well as to query the current state of the link processor. The link processor itself is responsible for handling the JESD204 link layer protocol.
Interfaces and Signals
Register Map Configuration Interface
The register map configuration interface can be accessed through the AXI4-Lite
S_AXI
interface. The interface is synchronous to the s_axi_aclk
. The
s_axi_aresetn
signal is used to reset the peripheral and should be asserted
during system startup until the s_axi_aclk
is active and stable.
De-assertion of the reset signal should by synchronous to s_axi_aclk
.
JESD204B Control Signals
The sync
and sysref
signals corresponds to the SYNC~ and SYSREF signals
of the JESD204 specification. These are signals generated externally and need to
be connected to the peripheral for correct operation.
In 8B/10B link layer the sysref
signal is optional and only required to
achieve deterministic latency in subclass 1 mode operation. If the sysref
signal is not connected software needs to configure the peripheral accordingly
to indicate this. In 64B/66B link layer the sysref
signal is mandatory.
When the sysref
signal is used, in order to ensure correct operation, it is
important that setup and hold of the external signal relative to the
device_clk
signal are met. Otherwise deterministic latency can not be
guaranteed.
Transceiver Interface (TX_PHYn)
For each lane the peripheral has one corresponding TX_PHY
interface. These
interfaces provide the pre-processed physical layer data. The TX_PHY interfaces
should be connected to the down-stream physical layer transceiver peripheral.
The physical layer peripheral receiving data from these interfaces are responsible for performing the final 8b10b mapping as well as serializing the data and transmitting it on the physical CML differential high-speed serial lane.
User Data Interface (TX_DATA)
User data is accepted on the the AXI4-Stream TX_DATA
interface. The
interface is a reduced AXI4-Stream interface and only features the TREADY flow
control signal, but not the TVALID flow control signal. The behavior of the
interface is as if the TVALID signal was always asserted. This means as soon as
tx_ready is asserted a continuous stream of user data must be provided on
tx_data.
After reset and during link initialization the tx_ready
signal is
de-asserted. As soon as the User Data Phase is
entered the tx_ready
will be asserted to indicate that the peripheral is now
accepting and processing the data from the tx_data
signal. The tx_ready
signal stays asserted until the link is either deactivated or re-initialized.
Typically the TX_DATA
interface is connected to a JESD204B transport layer
peripheral that provides framed and lane mapped data. The internal data path
width of the peripheral is four, this means that four octets per lane are
processed in parallel. When in the user data phase the peripheral expects to
receive data for four octets for each lane in each beat.
This means that TX_DATA
interface is DATA_PATH_WIDTH
* 8 *
NUM_LANES
bits wide. With each block of consecutive DATA_PATH_WIDTH
*
8 bits corresponding to one lane. The lowest DATA_PATH_WIDTH
* 8 bits
correspond to the first lane, while the highest DATA_PATH_WIDTH
* 8 bits
correspond to the last lane.
E.g. for 8B/10B mode where DATA_PATH_WIDTH=4. Each lane specific 32-bit block
corresponds to four octets each 8 bits wide. The temporal ordering of the
octets is from LSB to MSB, this means the octet placed in the lowest 8 bits is
transmitted first, the octet placed in the highest 8 bits is transmitted last.
Data corresponding to lanes that have been disabled are ignored and their value is don’t care.
Configuration Interface
The peripheral features a register map configuration interface that can be
accessed through the AXI4-Lite S_AXI
port. The register map can be used to
configure the peripherals operational parameters, query the current status of
the device and query the features supported by the device.
Peripheral Identification and HDL Synthesis Settings
The peripheral contains multiple registers that allow the identification of the
peripheral as well as the discovery of features that were configured at HDL
synthesis time. Apart from the SCRATCH
register all registers in this
section are read-only and write to them will be ignored.
The VERSION
(0x000
) register contains the version of the peripheral. The
version determines the register map layout and general features supported by the
peripheral. The version number follows semantic versioning.
Increments in the major number indicate backward incompatible changes,
increments in the minor number indicate backward compatible changes, patch
letter increments indicate a bug fix.
The PERIPHERAL_ID
(0x004
) register contains the value of the ID
HDL
configuration parameter that was set during synthesis. Its primary function is
to allow to distinguish between multiple instances of the peripheral in the same
design.
The SCRATCH
(0x008
) register is a general purpose 32-bit register that
can be set to an arbitrary values. Reading the register will yield the value
previously written (The value will be cleared when the peripheral is reset). Its
content does not affect the operation of the peripheral. It can be used by
software to test whether the register map is accessible or store custom
peripheral associated data.
The IDENTIFICATION
(0x00c
) register contains the value of "204T"
.
This value is unique to this type of peripheral and can be used to ensure that
the peripheral exists at the expected location in the memory mapped IO register
space.
The SYNTH_NUM_LANES
(0x010
) register contains the value of the
NUM_LANES
HDL configuration parameter that was set during synthesis. It
corresponds to the maximum of lanes supported by the peripheral. Possible values
are between 1
and 32
.
The SYNTH_DATA_PATH_WIDTH
(0x014
) register contains the value of the
internal data path width per lane in octets. This is how many octets are
processed in parallel on each lane and affects the restrictions of possible
values for certain runtime configuration registers. The value is encoded as the
log2() of the data path width. Possible values are:
Internal data path width is 2;
Internal data path width is 4;
Internal data path width is 8.
Interrupt Handling
Interrupt processing is handled by three closely related registers. All three registers follow the same layout, each bit in the register corresponds to one particular interrupt.
When an interrupt event occurs it is recorded in the IRQ_SOURCE
(0x088
)
register. For a recorded interrupt event the corresponding bit is set to 1. If
an interrupt event occurs while the bit is already set to 1 it will stay set to
1.
The IRQ_ENABLE
(0x080
) register controls how recorded interrupt events
propagate. An interrupt is considered to be enabled if the corresponding bit in
the IRQ_ENABLE
register is set to 1, it is considered to be disabled if the
bit is set to 0.
Disabling an interrupt will not prevent it from being recorded, but only its propagation. This means if an interrupt event was previously recorded while the interrupt was disabled and the interrupt is being enabled the interrupt event will then propagate.
An interrupt event that has been recorded and is enabled propagates to the
IRQ_PENDING
(0x084
) register. The corresponding bit for such an
interrupt will read as 1. Disabled or interrupts for which no events have been
recorded will read as 0. Also if at least one interrupt has been recorded and is
enabled the external irq
signal will be asserted to signal the IRQ event to
the upstream IRQ controller.
A recorded interrupt event can be cleared (or acknowledged) by writing a 1 to
the corresponding bit to either the IRQ_SOURCE
or IRQ_PENDING
register.
It is possible to clear multiple interrupt events at the same time by setting
multiple bits in a single write operation.
For more details regarding interrupt operation see the interrupts section of this document.
Link Control
The LINK_DISABLE
(0x0c0
) register is used to control the link state and
switch between enabled and disabled. While the link is disabled its state
machine will remain in reset and it will not react to any external event like
the SYSREF
or SYNC~
signals.
Writing a 0 to the LINK_DISABLE
register will enable the link. While the
link state is changing from disabled to enabled it will go through a short
initialization procedure, which will take a few clock cycles. To check whether
the initialization procedure has completed and the link is fully operational the
LINK_STATE
(0x0c4
) register can be checked. This register will contain a
0 when the link is fully enabled and will contain a 1 while it is disabled or
going through the initialization procedure.
Writing a 1 to the LINK_DISABLE
register will immediately disable the link.
The EXTERNAL_RESET
([1]
) bit in the LINK_STATE
register indicates
whether the external link reset signal is asserted (1
) or de-asserted
(0
). When the external link reset is asserted the link is disabled
regardless of the setting of LINK_DISABLE
. The external link reset is
controlled by the fabric and might be asserted if the link clock is not stable
yet.
Multi-link Control
A multi-link is a link where multiple converter devices are connected to a single logic device (FPGA). All links involved in a multi-link are synchronous and established at the same time. For an 8B/10B TX link, this means that the FPGA receives multiple SYNC signals, one for each link.
For a 8B/10B link the MULTI_LINK_DISABLE
register allows activating or
deactivating each SYNC~
lines independently. This is useful when depending
on the use case profile some converter devices are supposed to be disabled.
Link Configuration
The link configuration registers control certain aspects of the runtime behavior of the peripheral. Since the JESD204 standard does now allow changes to link configuration while the link is active the link configuration registers can only be modified while the link is disabled. As soon as it is enabled the configuration registers turn read-only and any writes to them will be ignored.
The LANES_DISABLE
(0x200
) register allows to disable individual lanes.
Each bit in the register corresponds to a particular lane and indicates whether
that lane is enabled or disabled. Bit 0 corresponds to the first lane, bit 1 to
the second lane and so on. A value of 0 for a specific bit means the
corresponding lane is enabled, a value of 1 means the lane is disabled. A
disabled lane will not transmit any data when the link is otherwise active. By
default, all lanes are enabled.
The LINK_CONF0
register configures the octets-per-frame and
frames-per-multi-frame settings of the link. The OCTETS_PER_FRAME
([18:16]
) field should be set to the number of octets-per-frame minus 1 (F -
1). The OCTETS_PER_MULTIFRAME
([9:0]
) field should be set to the number
of octets-per-frame multiplied by the number of frames-per-multi-frame minus 1
(FxK - 1). For correct operation FxK must be a multiple of DATA_PATH_WIDTH
.
In 64B/66B mode this field matches and also represents the number of octets per
extended multiblock (Ex32x8 - 1).
The LINK_CONF1
register controls the optional link level processing stages.
The SCRAMBLER_DISABLE
([0]
) bit controls whether scrambling of the
transmitted user data is enabled or disabled. A value of 0 enables scrambling
and a value of 1 disables it. In 64B/66B mode scrambling must be always enabled.
The CHAR_REPLACEMENT_DISABLE
([1]
) bit controls whether alignment
character replacement is performed or not. A value of 0 enables character
replacement and a value of 1 disables it. For correct operation, character
replacement must be disabled when scrambling is disabled otherwise undefined
behavior might occur.
Both the transmitter as well as receiver device on the JESD204 link need to be configured with the same settings for scrambling/descrambling and character replacement for correct operation.
It is recommended to leave both scrambling as well as alignment character replacement enabled during normal operation and only disable it for debugging or testing purposes.
Character replacement is used only in 8B/10B links and completely disregarded in 64B/66B mode.
The LINK_CONF2
(0x240
) register contains configuration data that affects
the transitions of the link state machine. If the
CONTINUOUS_CGS
([0]
) bit is set the state machine will remain in the CGS
phase indefinitely and send repeated /K/ control character.
If the CONTINUOUS_ILAS
([1]
) bit is set the state machine will remain
in the ILAS phase indefinitely and send repeated ILAS sequences. If the
SKIP_ILAS
([2]
) bit is set the state machine will directly transition
to the DATA phase from the CGS phase without going through the ILAS phase.
The LINK_CONFIG2
register is used only in 8B/10B links and completely
disregarded in 64B/66B mode.
The LINK_CONF3
(0x244
) register configures the duration of the ILAS
sequence in number of multi-frames. Its value is equal to the number of
multi-frames minus one. In the current iteration of the peripheral, this
register is read-only and the ILAS will always last for four multi-frames. The
LINK_CONFIG3
register is used only in 8B/10B links and completely
disregarded in 64B/66B mode.
ILAS Configuration Data
For 8B/10B link layer the ILAS configuration data registers contain the configuration data that is sent during the ILAS phase. Similar to the link configuration registers, the ILAS configuration data registers can only be modified while the link is disabled and turn read-only as soon as it is enabled.
For each lane there is a set of four registers (LANEn_ILAS0
,
LANEn_ILAS1
, LANEn_ILAS2
, LANEn_ILAS3
) that allow access to the 14
configuration data octets. Aside from the LID
and FCHK
fields all fields
for each of the lanes map to the same internal storage. This means only the
LID
and FCHK
fields can be configured with per-lane configuration data,
all other fields must be set to the same value for all lanes.
SYSREF Handling
The external SYSREF signal is used to align the internal local multiframe clocks (LMFC)/ local-multiblock-clock (LEMC) between multiple devices on the same link.
The SYSREF_CONF
(0x100
) register controls the behavior of the SYSREF
capture circuitry. Setting the SYSREF_DISABLE
([0]
) bit to 1 disables
the SYSREF handling. All external SYSREF events are ignored and the LMFC/LEMC is
generated internally. For Subclass 1 operation SYSREF handling should be enabled
and for Subclass 0 operation it should be disabled.
The SYSREF_LMFC_OFFSET
(0x104
) register allows modifying the offset
between the SYSREF rising edge and the rising edge of the LMFC/LEMC. Must be a
multiple of DATA_PATH_WIDTH
.
For optimal operation, it is recommended that all device on a JESD204 link should be configured in a way so that the total offset between
The value of the SYSREF_LMFC_OFFSET
register must be set to a value smaller
than the configured number of octets-per-multiframe (OCTETS_PER_MULTIFRAME
),
otherwise undefined behavior might occur.
The SYSREF_STATUS
(0x108
) register allows monitoring the status of the
SYSREF signals. SYSREF_DETECTED
([0]
) bit indicates that the peripheral
as observed a SYSREF event. The SYSREF_ALIGNMENT_ERROR
([1]
) bit
indicates that a SYSREF event has been observed which was unaligned, in regards
to the LMFC period, to a previously recorded SYSREF event.
All bits in the SYSREF_STATUS
register are write-to-clear. All bits will
also be cleared when the link is disabled.
Note that the SYSREF_STATUS
register will not record any events if SYSREF
operation is disabled or the JESD204 link is disabled.
Link Status
All link status registers are read-only. While the link is disabled some of the link status registers might contain bogus values. Their content should be ignored until the link is fully enabled.
The STATUS_STATE
([1:0]
) field of the LINK_STATUS
(0x280
)
register indicates the state of the
8B/10B link state machine
or 64B/66B link state machine depending on the selected encoder. Possible
values are:
Possible values for a 8B/10B link are:
0: WAIT phase;
1: CGS phase;
2: ILAS phase;
3: DATA phase.
Possible values for a 64B/66B link are:
0: WAIT phase;
3: DATA phase.
The STATUS_SYNC
([4]
) field represents the raw state of the external
SYNC~ and can be used to monitor whether the JESD204B converter device has
requested link synchronization. This is available only for 8B/10B links.
Manual Synchronization Request
For 8B/10B links the MANUAL_SYNC_REQUEST
(0x248
) register can be used to
transition the link state from the WAIT phase to the CGS phase in the absence of
an external synchronization request. This is useful for test cases where the
peripheral is connected to signal analyzer instead of a JESD204B receiver
device.
Writing a 1 to this register will trigger a manual synchronization request. Writing the register while the link is disabled or writing a 0 to the register has no effect. The register is self-clearing and reading it will always return 0.
This feature is useful if the SYNC~
is stuck high from some reason. Setting
the MANUAL_SYNC_REQUEST
bit will bring out the Tx link peripheral from
CGS
and will continue with sending ILAS
and DATA
information. After
this, the SYNC_STATUS
bit would read high, and LINK_STATE
would be
DATA
.
If the SYNC~
is stuck low, writing the MANUAL_SYNC_REQUEST
would not do
too much, the link would stay in CGS
and wait the de-assertion of SYNC~
which won’t happen. In this case the SYNC_STATUS
would stay low and
LINK_STATE
would be CGS
.
Clock Monitor
The LINK_CLK_FREQ
(0x0c8
) register allows to determine the clock rate of
the link clock (clk
) relative to the AXI interface clock (s_axi_aclk
).
This can be used to verify that the link clock is running at the expected rate.
The DEVICE_CLK_FREQ
(0x0cc
) register allows to determine the clock rate
of the device clock (device_clk
) relative to the AXI interface clock
(s_axi_aclk
). This can be used to verify that the device clock is running at
the expected rate.
The number is represented as unsigned 16.16 format. Assuming a 100MHz processor clock this corresponds to a resolution of 1.523kHz per LSB. A raw value of 0 indicates that the link clock is currently not active.
Interrupts
The core does not generate interrupts.
8B/10B Link
8B/10B Link State Machine
The peripheral can be in one of four main operating phases: WAIT, CGS, ILAS or DATA. Upon reset the peripheral starts in the WAIT phase. The CGS and ILAS phases are used during the initialization of the JESD204B link. The DATA phase is used during normal operation when user data is transmitted across the JESD204B link.
Wait Phase (WAIT)
The WAIT phase is the default state entered during reset. While disabled the peripheral will stay in the WAIT phase. When enabled, the peripheral will stay in the WAIT phase until a synchronization request is received.
A synchronization request can either be generated manually through the register
map configuration interface or by one of the JESD204B receivers by asserting the
SYNC~
signal. Once a synchronization request is received the peripheral
transitions to the CGS phase.
During the WAIT phase the peripheral will continuously transmit
/K/ control character
on each of the TX_PHYn
interfaces.
If at any point the peripheral is disabled, it will automatically transition back to the WAIT state.
Lanes that have been disabled in the register map configuration interface, will behave as if the link was in the WAIT state regardless of the actual state.
Code Group Synchronization Phase (CGS)
During the CGS phase the peripheral will continuously transmit
/K/ control character
on each of the TX_PHYn
interfaces.
The peripheral will stay in the CGS phase until all of following conditions are satisfied:
The synchronization request is de-asserted;
The CGS phase has lasted for at least the configured minimum CGS duration (1 frame + 9 octets by default);
The end of a multi-frame is reached (This means the next phase will start at the beginning of a multi-frame);
The SYSREF signal has been captured and the LMFC is properly aligned.
If the peripheral is configured for continuous CGS operation it will stay in the CGS phase indefinitely regardless of whether the above conditions are met or not.
By default the peripheral will transition to the ILAS phase at the end of the CGS phase. If the core is configured to skip the ILAS phase it will instead directly transition to the DATA phase.
Initial Lane Alignment Sequence Phase (ILAS)
During the ILAS phase the peripheral transmits the initial lane alignment sequence. The transmitted ILAS consists of four multi-frames. The first octet of each multi-frame is the /R/ control character and the last octet of each multi-frame is the /A/ control character.
During the second multi-frame the link configuration data is transmitted from the 3rd to 16th octet. The second octet of the second multi-frame is the /Q/ control character to indicate that this multi-frame carries configuration data. The ILAS configuration data sequence can be programmed through the register map configuration interface.
All other octets of the ILAS sequence will contain the numerical value corresponding to the position of the octet in the ILAS sequence (E.g. the fifth octet of the first multi-frame contains the value 4).
By default the ILAS is transmitted for a duration of 4 multi-frames. After the last ILAS multi-frame the peripheral switches to the DATA phase.
If the peripheral is configured for continuous ILAS operation it will instead remain in the ILAS phase indefinitely. In continuous ILAS mode the peripheral will transition back to the first multi-frame of the ILAS sequence after the last multi-frame has been transmitted.
In accordance with the JESD204B standard the data transmitted during the ILAS phase is not scrambled regardless of whether scrambling is enabled or not.
User Data Phase (DATA)
The DATA phase is the main operating mode of the peripheral. In this phase it
will receive transport layer data at the TX_DATA
port, split it onto the
corresponding lanes and perform per-lane processing of the data according to the
peripherals configuration. When the peripheral enters the DATA phase the
ready
signal of the TX_DATA
will be asserted to indicate that transport
layer data is now accepted.
By default the data transmitted on each lane will be scrambled. Scrambling can optionally be disabled via the register map configuration interface. Scrambling is enabled or disabled for all lanes equally.
Scrambling reduces data-dependent effects, which can affect both the analog performance of the data converter as well as the bit-error rate of JESD204B serial link, therefore it is highly recommended to enable scrambling.
The peripheral also performs per-lane alignment character replacement. Alignment character replacement will replace under certain predictable conditions (i.e. the receiver can recover the replaced character) the last octet in a frame or multi-frame. Replaced characters at the end of a frame, that is also the end of a multi-frame, are replaced by the /A/ character. Replaced characters at the end of a frame, that is not the end of a multi-frame, are replaced by the /F/ character. Alignment characters can be used by the receiver to ensure proper frame and lane alignment.
Alignment character replacement can optionally be disabled via the register map configuration interface. Alignment character replacement is enabled or disabled for all lanes equally. Alignment character replacement is only available when scrambling is enabled and must be disabled when scrambling is disabled, otherwise undefined behavior might occur.
Data on the TX_DATA
port corresponding to a disabled lane is ignored.
8B/10B Multi-endpoint TX link establishment
In a multi-endpoint configuration one link transmit peripheral connects to
several endpoints/converter devices. In such cases the link is established
only when all enabled endpoints reach the DATA phase. For that all endpoints
must pass through CGS and ILAS stages. Depending on the software
implementation that controls the converter devices the endpoints can be
enabled at different moments. The link transmit peripheral will send CGS
characters until all enabled endpoints succeeded character alignment and
signalize that through the de-assertion of SYNC~
signal.
In the below example we have a multi-point link of four endpoints
(NUM_LINKS
= 4):
Note
The physical layer is not depicted on purpose. JRXn represents the link layer counterpart in the converter device/endpoint n.
The steps of the link bring-up are presented below:
1 - Link transmit peripheral is enabled, will start to send
CGS
characters on all lanes regardless of the state of theSYNC~
signal;2,3,4,5 - JESD Receive block of ADC enabled, its corresponding
SYNC~
pin is pulled low. The timing depends on the software implementation that controls the ADC;6 - In Subclass 1 (SC1)
SYSREF
is captured andLMFC
in the FPGA and converter device is adjusted;7 - Once the
CGS
characters are received correctly, on the next Frame clock boundary in SC0 orLMFC
boundary in SC1 theSYNC~
is de-asserted;8 - Once all enabled endpoints (not masked by
MULTI_LINK_DISABLE
) de-assert theSYNC~
signal, on the next Frame clock boundary for SC0 or the nextLMFC
boundary for SC1, the transmit peripheral will start sending theILAS
sequence, thenMFRAMES_PER_ILAS
(typically 4)LMFC
periods later the actualDATA
. In SC1 ifSYSREF
is not captured the link transmit peripheral will stay in CGS state.
Diagnostics
64B/66B Link
The 64-bit wide datapath of the link layer is fairly simple, the only mandatory
part of the 64B66B link layer datapath is the scrambler. This must be active
during the operation of the link, however for debug purposes can be bypasses
with a control register SCRAMBLER_DISABLE
.
The data is accepted from the upstream transport layer core once the local extended multiblock clock (LEMC) is adjusted to the captured SYSREF signal. Once this happened the data will be accepted without interruption until the link is disabled since there is no back-pressure from the physical layer.
If the core does not receives at least one SYSREF pulse it will not pass any data from transport layer to physical layer.
For each multiblock sent on the data interface a CRC is calculated which is sent on the 2-bit sync header stream during the next multiblock period. Beside the CRC the sync header stream contains synchronization information to mark the boundary of the multiblock and extended multiblocks.
Dual clock operation
In case ASYNC_CLK
parameter is set, a gearbox with 4:N (204B) or 8:N (204C)
ratio is enabled in the link layer peripherals, where N depends on the F
parameter of the link. The goal of the gearbox is to have at the transport
layer interface a data width that contains an integer number of frames per
every device clock cycle (each beat) so an integer number of samples can be
delivered/consumed to/from the application layer aligned to SYSREF ensuring
deterministic latency in modes where N’=12 or F!=1,2,4.
The gearbox ratio corresponds with the ratio of the link layer interface data width towards physical layer and transport layer in octets. The interface width towards the physical layer in 8B/10B (204B) mode depends on the DATA_PATH_WIDTH synthesis parameter, and can be either 4 octets (default) or 8 octets. In 204B mode the util_adxcvr supports only data width of 4 octets. In 64b66b (aka 204C) mode the data width towards the physical interface is always 8 octets.
The data path width towards the transport layer is defined by the TPL_DATA_PATH_WIDTH synthesis parameter.
The following rules apply:
TPL_DATA_PATH_WIDTH >= DATA_PATH_WIDTH;
TPL_DATA_PATH_WIDTH = m x F; where m is a positive integer, power of 2.
The link clock and device clock ratio should be the inverse of the DATA_PATH_WIDTH : TPL_DATA_PATH_WIDTH ratio.
In this context the link clock will be lane rate/40 or lane rate/80 for 204B depending on DATA_PATH_WIDTH and lane rate / 66 for 204C 64B/66B, however the device clock could vary based in the F parameter.
Software Support
Warning
To ensure correct operation it is highly recommended to use the Analog Devices provided JESD204B software packages for interfacing the peripheral. Analog Devices is not able to provide support in case issues arise from using custom low-level software for interfacing the peripheral.
Restrictions
During the design of the peripheral the deliberate decision was made to support only a subset of the features mandated by the JESD204B standard for transmitter logic devices. The reasoning here is that the peripheral has been designed to interface to Analog Devices JESD204B DAC converter devices and features that are either not required or not supported by those converter devices would otherwise lie dormant in peripheral and never be used. Instead the decision was made to not implement those unneeded features even when the JESD204B standard requires them for general purpose JESD204B transmitter logic devices. As Analog Devices DAC converter devices with new requirements are released the peripheral will be adjusted accordingly.
This approach allows for a leaner design using less resources, allowing for lower pipeline latency and a higher maximum device clock frequency.
The following lists where the peripheral deviates from the standard:
No subclass 2 support. JESD204B subclass 2 has due to its implementation details restricted applicability and is seldom a viable option for a modern high-speed data converter system. To achieve deterministic latency it is recommend to use subclass 1 mode;
Reduced number of octets-per-frame settings. The JESD204B standard allows for any value between 1 and 256 to be used for the number of octets-per-frame;
The following octets-per-frame values are supported by the peripheral: 1, 2, 4 and 8.(No longer applies starting from 1.06.a);
Reduced number of frames-per-multi-frame settings. The following values are supported by the peripheral: 1-32, with the additional requirement that F*K is a multiple of 4. In addition F*K needs to be in the range of 4-256;
No support for alignment character replacement when scrambling is disabled.(No longer applies starting from 1.06.a).
Supported Devices
JESD204B Digital-to-Analog Converters
AD9135: Dual, 11-Bit, high dynamic, 2.8 GSPS, TxDAC+® Digital-to-Analog Converter
AD9136: Dual, 16-Bit, 2.8 GSPS, TxDAC+® Digital-to-Analog Converter
AD9144: Quad, 16-Bit, 2.8 GSPS, TxDAC+® Digital-to-Analog Converter
AD9152: Dual, 16-Bit, 2.25 GSPS, TxDAC+ Digital-to-Analog Converter
AD9154: Quad, 16-Bit, 2.4 GSPS, TxDAC+® Digital-to-Analog Converter
AD9161: 11-Bit, 12 GSPS, RF Digital-to-Analog Converter
AD9162: 16-Bit, 12 GSPS, RF Digital-to-Analog Converter
AD9163: 16-Bit, 12 GSPS, RF DAC and Digital Upconverter
AD9164: 16-Bit, 12 GSPS, RF DAC and Direct Digital Synthesizer
AD9172: Dual, 16-Bit, 12.6 GSPS RF DAC with Channelizers
AD9173: Dual, 16-Bit, 12.6 GSPS RF DAC with Channelizers
AD9174: Dual, 16-Bit, 12.6 GSPS RF DAC and Direct Digital Synthesizer
AD9175: Dual, 11-Bit/16-Bit, 12.6 GSPS RF DAC with Wideband Channelizers
AD9176: Dual, 16-Bit, 12.6 GSPS RF DAC with Wideband Channelizers
AD9177: Quad, 16-Bit, 12 GSPS RF DAC with Wideband Channelizers
JESD204B RF Transceivers
AD9371: SDR Integrated, Dual RF Transceiver with Observation Path
AD9375: SDR Integrated, Dual RF Transceiver with Observation Path and DPD
ADRV9009: SDR Integrated, Dual RF Transceiver with Observation Path
ADRV9008-1: SDR Integrated, Dual RF Receiver
ADRV9008-2: SDR Integrated, Dual RF Transmitter with Observation Path
JESD204B/C Mixed-Signal Front Ends
Technical Support
Analog Devices will provide limited online support for anyone using the core with Analog Devices components (ADC, DAC, Clock, etc) via the EngineerZone under the GPL license. If you would like deterministic support when using this core with an ADI component, please investigate a commercial license. Using a non-ADI JESD204 device with this core is possible under the GPL, but Analog Devices will not help with issues you may encounter.