AXI AD408x

The AXI AD408x IP core can be used to interface the AD4080 device. This documentation only covers the IP core and requires one to be familiar with the device, for a complete and better understanding.

More about the generic framework interfacing ADCs can be read in Generic AXI ADC.

Features

  • AXI Lite control/status interface

  • Programmable line delays

  • DDR data stream selection

  • Single/dual lane data stream selection

  • Bit-slip capability for synchronization

  • Filtered data support

  • Programmable decimation rate support

  • Xilinx devices compatible

Files

Name

Description

library/axi_ad408x/axi_ad408x.v

Verilog source for the AXI AD408x.

library/axi_ad408x/ad408x_phy.v

Verilog source for the AXI AD408x physical interface.

library/axi_ad408x/axi_ad408x_ip.tcl

IP definition file (AMD tools)

Block Diagram

AXI AD408x block diagram

Configuration Parameters

Name

Description

Default Value

Choices/Range

ID

Core ID should be unique for each IP in the system

0

FPGA_TECHNOLOGY

Used to select between FPGA devices, auto set in project.

0

Unknown (0), 7series (1), ultrascale (2), ultrascale+ (3), versal (4)

Interface

Physical Port

Logical Port

Direction

Dependency

s_axi_awaddr AWADDR

in [15:0]

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 [15:0]

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

adc_clk CLK

out

Physical Port

Logical Port

Direction

Dependency

delay_clk CLK

in

Physical Port

Direction

Dependency

Description

dclk_in_p

in

LVDS input positive side of differential reference clock signal

dclk_in_n

in

LVDS input negative side of differential reference clock signal

data_a_in_p

in

LVDS input positive side of differential data line A signal

data_a_in_n

in

LVDS input negative side of differential data line A signal

data_b_in_p

in

LVDS input positive side of differential data line B signal

data_b_in_n

in

LVDS input negative side of differential data line B signal

cnv_in_p

in

LVDS input positive side of differential CNV signal

cnv_in_n

in

LVDS input negative side of differential CNV signal

sync_n

in

Signals when the clock is disabled and the design should be in reset

filter_data_ready_n

in

Signals when the filtered data is ready at the interface

adc_data

out [31:0]

Received data output

adc_valid

out

Indicates valid data

adc_dovf

in

Data overflow. Must be connected to the DMA

Internal Interface Description

The axi_ad408x operates as follows:

  • The LVDS data is deserialized by the ad_serdes_in module with a 1:8 ratio.

  • After deserialization, the data is sent to the ad_pack module, which packs the 8-bit data into a 20-bit format.

  • When the bit-slip (synchronization process) is enabled, the software configures the ADC to output a fixed pattern, and the interface module will adjust the data alignment until the pattern is captured.

  • When the filter is enabled, the adc_valid signal is gated by the filter_data_ready_n signal, and the data is sent to the output only when the filtered data is available.

Register Map

The register map of the core contains instances of several generic register maps like ADC common, ADC channel, up_delay_cntrl. The following table presents the base addresses of each instance, after it you can find the detailed description of each generic register map.

The absolute address of a register should be calculated by adding the instance base address to the registers relative address.

Register Map base addresses for axi_ad408x

DWORD

BYTE

Name

Description

0x0000

0x0000

BASE

See the Base table for more details.

0x0000

0x0000

RX COMMON

See the ADC Common table for more details.

0x0000

0x0000

RX CHANNELS

See the ADC Channel table for more details.

0x0000

0x0800

IO_DELAY_CNTRL

See the I/O Delay Control table for more details.

DWORD

BYTE

Reg Name

Description

BITS

Field Name

Type

Default Value

Description

0x0 0x0 VERSION

Version and Scratch Registers

[31:0] VERSION RO 0x00000000

Version number. Unique to all cores.

0x1 0x4 ID

Version and Scratch Registers

[31:0] ID RO 0x00000000

Instance identifier number.

0x2 0x8 SCRATCH

Version and Scratch Registers

[31:0] SCRATCH RW 0x00000000

Scratch register.

0x3 0xc CONFIG

Version and Scratch Registers

[0] IQCORRECTION_DISABLE RO 0x0

If set, indicates that the IQ Correction module was not implemented. (as a result of a configuration of the IP instance)

[1] DCFILTER_DISABLE RO 0x0

If set, indicates that the DC Filter module was not implemented. (as a result of a configuration of the IP instance)

[2] DATAFORMAT_DISABLE RO 0x0

If set, indicates that the Data Format module was not implemented. (as a result of a configuration of the IP instance)

[3] USERPORTS_DISABLE RO 0x0

If set, indicates that the logic related to the User Data Format (e.g. decimation) was not implemented. (as a result of a configuration of the IP instance)

[4] MODE_1R1T RO 0x0

If set, indicates that the core was implemented in 1 channel mode. (e.g. refer to AD9361 data sheet)

[5] DELAY_CONTROL_DISABLE RO 0x0

If set, indicates that the delay control is disabled for this IP. (as a result of a configuration of the IP instance)

[6] DDS_DISABLE RO 0x0

If set, indicates that the DDS is disabled for this IP. (as a result of a configuration of the IP instance)

[7] CMOS_OR_LVDS_N RO 0x0

CMOS or LVDS mode is used for the interface. (as a result of a configuration of the IP instance)

[8] PPS_RECEIVER_ENABLE RO 0x0

If set, indicates the PPS receiver is enabled. (as a result of a configuration of the IP instance)

[9] SCALECORRECTION_ONLY RO 0x0

If set, indicates that the IQ Correction module implements only scale correction. IQ correction must be enabled. (as a result of a configuration of the IP instance)

[12] EXT_SYNC RO 0x0

If set the transport layer cores (ADC/DAC) have implemented the support for external synchronization signal.

[13] RD_RAW_DATA RO 0x0

If set, the ADC has the capability to read raw data in register CHAN_RAW_DATA from adc_channel.

0x4 0x10 PPS_IRQ_MASK

PPS Interrupt mask

[0] PPS_IRQ_MASK RW 0x1

Mask bit for the 1PPS receiver interrupt

0x7 0x1c FPGA_INFO

FPGA device information library/scripts/adi_intel_device_info_enc.tcl (Intel encoded values) library/scripts/adi_xilinx_device_info_enc.tcl (Xilinx encoded values)

[31:24] FPGA_TECHNOLOGY RO 0x00

Encoded value describing the technology/generation of the FPGA device (arria 10/7series)

[23:16] FPGA_FAMILY RO 0x00

Encoded value describing the family variant of the FPGA device(e.g., SX, GX, GT or zynq, kintex, virtex)

[15:8] SPEED_GRADE RO 0x00

Encoded value describing the FPGA’s speed-grade

[7:0] DEV_PACKAGE RO 0x00

Encoded value describing the device package. The package might affect high-speed interfaces

DWORD

BYTE

Reg Name

Description

BITS

Field Name

Type

Default Value

Description

0x10 0x40 RSTN

ADC Interface Control & Status

[2] CE_N RW 0x0

Clock enable, default is enabled(0x0). An inverse version of the signal is exported out of the module to control clock enables

[1] MMCM_RSTN RW 0x0

MMCM reset only (required for DRP access). Reset, default is IN-RESET (0x0), software must write 0x1 to bring up the core.

[0] RSTN RW 0x0

Reset, default is IN-RESET (0x0), software must write 0x1 to bring up the core.

0x11 0x44 CNTRL

ADC Interface Control & Status

[16] SDR_DDR_N RW 0x0

Interface type (1 represents SDR, 0 represents DDR)

[15] SYMB_OP RW 0x0

Select symbol data format mode (0x1)

[14] SYMB_8_16B RW 0x0

Select number of bits for symbol format mode (1 represents 8b, 0 represents 16b)

[12:8] NUM_LANES RW 0x00

Number of active lanes (1 : CSSI 1-lane, LSSI 1-lane, 2 : LSSI 2-lane, 4 : CSSI 4-lane). For AD7768, AD7768-4 and AD777x number of active lanes : 1/2/4/8 where supported.

[3] SYNC RW 0x0

Initialize synchronization between multiple ADCs

[2] R1_MODE RW 0x0

Select number of RF channels 1 (0x1) or 2 (0x0).

[1] DDR_EDGESEL RW 0x0

Select rising edge (0x0) or falling edge (0x1) for the first part of a sample (if applicable) followed by the successive edges for the remaining parts. This only controls how the sample is delineated from the incoming data post DDR registers.

[0] PIN_MODE RW 0x0

Select interface pin mode to be clock multiplexed (0x1) or pin multiplexed (0x0). In clock multiplexed mode, samples are received on alternative clock edges. In pin multiplexed mode, samples are interleaved or grouped on the pins at the same clock edge.

0x12 0x48 CNTRL_2

ADC Interface Control & Status

[1] EXT_SYNC_ARM RW 0x0

Setting this bit will arm the trigger mechanism sensitive to an external sync signal. Once the external sync signal goes high it synchronizes channels within a ADC, and across multiple instances. This bit has an effect only the EXT_SYNC synthesis parameter is set. This bit self clears.

[2] EXT_SYNC_DISARM RW 0x0

Setting this bit will disarm the trigger mechanism sensitive to an external sync signal. This bit has an effect only the EXT_SYNC synthesis parameter is set. This bit self clears.

[8] MANUAL_SYNC_REQUEST RW 0x0

Setting this bit will issue an external sync event if it is hooked up inside the fabric. This bit has an effect only the EXT_SYNC synthesis parameter is set. This bit self clears.

0x13 0x4c CNTRL_3

ADC Interface Control & Status

[8] CRC_EN RW 0x0

Setting this bit will enable the CRC generation.

[7:0] CUSTOM_CONTROL RW 0x00

Select output format decode mode.(for ADAQ8092: bit 0 - enables digital output randomizer decode , bit 1 - enables alternate bit polarity decode).

0x15 0x54 CLK_FREQ

ADC Interface Control & Status

[31:0] CLK_FREQ RO 0x00000000

Interface clock frequency. This is relative to the processor clock and in many cases is 100MHz. The number is represented as unsigned 16.16 format. Assuming a 100MHz processor clock the minimum is 1.523kHz and maximum is 6.554THz. The actual interface clock is CLK_FREQ * CLK_RATIO (see below). Note that the actual sampling clock may not be the same as the interface clock- software must consider device specific implementation parameters to calculate the final sampling clock.

0x16 0x58 CLK_RATIO

ADC Interface Control & Status

[31:0] CLK_RATIO RO 0x00000000

Interface clock ratio - as a factor actual received clock. This is implementation specific and depends on any serial to parallel conversion and interface type (ddr/sdr/qdr).

0x17 0x5c STATUS

ADC Interface Control & Status

[4] ADC_CTRL_STATUS RO 0x0

If set, indicates that the device’​s register data is available on the data bus.

[3] PN_ERR RO 0x0

If set, indicates pn error in one or more channels.

[2] PN_OOS RO 0x0

If set, indicates pn oos in one or more channels.

[1] OVER_RANGE RO 0x0

If set, indicates over range in one or more channels.

[0] STATUS RO 0x0

Interface status, if set indicates no errors. If not set, there are errors, software may try resetting the cores.

0x18 0x60 DELAY_CNTRL

ADC Interface Control & Status(Deprecated from version 9)

[17] DELAY_SEL RW 0x0

Delay select, a 0x0 to 0x1 transition in this register initiates a delay access controlled by the registers below.

[16] DELAY_RWN RW 0x0

Delay read (0x1) or write (0x0), the delay is accessed directly (no increment or decrement) with an address corresponding to each pin, and data corresponding to the total delay.

[15:8] DELAY_ADDRESS RW 0x00

Delay address, the range depends on the interface pins, data pins are usually at the lower range.

[4:0] DELAY_WDATA RW 0x00

Delay write data, a value of 1 corresponds to (1/200)ns for most devices.

0x19 0x64 DELAY_STATUS

ADC Interface Control & Status(Deprecated from version 9)

[9] DELAY_LOCKED RO 0x0

Indicates delay locked (0x1) state. If this bit is read 0x0, delay control has failed to calibrate the elements.

[8] DELAY_STATUS RO 0x0

If set, indicates busy status (access pending). The read data may not be valid if this bit is set.

[4:0] DELAY_RDATA RO 0x00

Delay read data, current delay value in the elements

0x1a 0x68 SYNC_STATUS

ADC Synchronization Status register

[0] ADC_SYNC RO 0x0

ADC synchronization status. Will be set to 1 after the synchronization has been completed or while waiting for the synchronization signal in JESD204 systems.

0x1c 0x70 DRP_CNTRL

ADC Interface Control & Status

[28] DRP_RWN RW 0x0

DRP read (0x1) or write (0x0) select (does not include GTX lanes). NOT-APPLICABLE if DRP_DISABLE is set (0x1).

[27:16] DRP_ADDRESS RW 0x000

DRP address, designs that contain more than one DRP accessible primitives have selects based on the most significant bits (does not include GTX lanes). NOT-APPLICABLE if DRP_DISABLE is set (0x1).

[15:0] RESERVED RO 0x0000

Reserved for backward compatibility.

0x1d 0x74 DRP_STATUS

ADC Interface Control & Status

[17] DRP_LOCKED RO 0x0

If set indicates that the DRP has been locked.

[16] DRP_STATUS RO 0x0

If set indicates busy (access pending). The read data may not be valid if this bit is set (does not include GTX lanes). NOT-APPLICABLE if DRP_DISABLE is set (0x1).

[15:0] RESERVED RO 0x0000

Reserved for backward compatibility.

0x1e 0x78 DRP_WDATA

ADC DRP Write Data

[15:0] DRP_WDATA RW 0x0000

DRP write data (does not include GTX lanes). NOT-APPLICABLE if DRP_DISABLE is set (0x1).

0x1f 0x7c DRP_RDATA

ADC DRP Read Data

[15:0] DRP_RDATA RO 0x0000

DRP read data (does not include GTX lanes).

0x20 0x80 ADC_CONFIG_WR

ADC Write Configuration ​Data

[31:0] ADC_CONFIG_WR RW 0x00000000

Custom ​Write to the available registers.

0x21 0x84 ADC_CONFIG_RD

ADC Read Configuration ​Data

[31:0] ADC_CONFIG_RD RO 0x00000000

Custom read of the available registers.

0x22 0x88 UI_STATUS

User Interface Status

[2] UI_OVF RW1C 0x0

User Interface overflow. If set, indicates an overflow occurred during data transfer at the user interface (FIFO interface). Software must write a 0x1 to clear this register bit.

[1] UI_UNF RW1C 0x0

User Interface underflow. If set, indicates an underflow occurred during data transfer at the user interface (FIFO interface). Software must write a 0x1 to clear this register bit.

[0] UI_RESERVED RW1C 0x0

Reserved for backward compatibility.

0x23 0x8c ADC_CONFIG_CTRL

ADC RD/WR configuration

[31:0] ADC_CONFIG_CTRL RW 0x00000000

Control RD/WR requests to the device’​s register map: bit 1 - RD (‘b1) , WR (‘b0), bit 0 - enable WR/RD operation.

0x28 0xa0 USR_CNTRL_1

ADC Interface Control & Status

[7:0] USR_CHANMAX RW 0x00

This indicates the maximum number of inputs for the channel data multiplexers. User may add different processing modules post data capture as another input to this common multiplexer. NOT-APPLICABLE if USERPORTS_DISABLE is set (0x1).

0x29 0xa4 ADC_START_CODE

ADC Synchronization start word

[31:0] ADC_START_CODE RW 0x00000000

This sets the startcode that is used by the ADCs for synchronization NOT-APPLICABLE if START_CODE_DISABLE is set (0x1).

0x2e 0xb8 ADC_GPIO_IN

ADC GPIO inputs

[31:0] ADC_GPIO_IN RO 0x00000000

This reads auxiliary GPI pins of the ADC core

0x2f 0xbc ADC_GPIO_OUT

ADC GPIO outputs

[31:0] ADC_GPIO_OUT RW 0x00000000

This controls auxiliary GPO pins of the ADC core NOT-APPLICABLE if GPIO_DISABLE is set (0x1).

0x30 0xc0 PPS_COUNTER

PPS Counter register

[31:0] PPS_COUNTER RO 0x00000000

Counts the core clock cycles (can be a device clock or interface clock) between two 1PPS pulse.

0x31 0xc4 PPS_STATUS

PPS Status register

[0] PPS_STATUS RO 0x0

If this bit is asserted there is no incomming 1PPS signal. Maybe the source is out of sync or it’s not active.

DWORD

BYTE

Reg Name

Description

BITS

Field Name

Type

Default Value

Description

0x100 + 0x16*n 0x400 + 0x58*n CHAN_CNTRLn

ADC Interface Control & Status Where n is from 0 to 15.

[11] ADC_LB_OWR RW 0x0

If set, forces ADC_DATA_SEL to 1, enabling data loopback

[10] ADC_PN_SEL_OWR RW 0x0

If set, forces ADC_PN_SEL to 0x9, device specific pn (e.g. ad9361) If both ADC_PN_TYPE_OWR and ADC_PN_SEL_OWR are set, they are ignored

[9] IQCOR_ENB RW 0x0

if set, enables IQ correction or scale correction. NOT-APPLICABLE if IQCORRECTION_DISABLE is set (0x1).

[8] DCFILT_ENB RW 0x0

if set, enables DC filter (to disable DC offset, set offset value to 0x0). NOT-APPLICABLE if DCFILTER_DISABLE is set (0x1).

[6] FORMAT_SIGNEXT RW 0x0

if set, enables sign extension (applicable only in 2’s complement mode). The data is always sign extended to the nearest byte boundary. NOT-APPLICABLE if DATAFORMAT_DISABLE is set (0x1).

[5] FORMAT_TYPE RW 0x0

Select offset binary (0x1) or 2’s complement (0x0) data type. This sets the incoming data type and is required by the post processing modules for any data conversion. NOT-APPLICABLE if DATAFORMAT_DISABLE is set (0x1).

[4] FORMAT_ENABLE RW 0x0

Enable data format conversion (see register bits above). NOT-APPLICABLE if DATAFORMAT_DISABLE is set (0x1).

[3] RESERVED RO 0x0

Reserved for backward compatibility.

[2] RESERVED RO 0x0

Reserved for backward compatibility.

[1] ADC_PN_TYPE_OWR RW 0x0

If set, forces ADC_PN_SEL to 0x1, modified pn23 If both ADC_PN_TYPE_OWR and ADC_PN_SEL_OWR are set, they are ignored

[0] ENABLE RW 0x0

If set, enables channel. A 0x0 to 0x1 transition transfers all the control signals to the respective channel processing module. If a channel is part of a complex signal (I/Q), even channel is the master and the odd channel is the slave. Though a single control is used, both must be individually selected.

0x101 + 0x16*n 0x404 + 0x58*n CHAN_STATUSn

ADC Interface Control & Status Where n is from 0 to 15.

[12] CRC_ERR RW1C 0x0

CRC errors. If set, indicates CRC error. Software must first clear this bit before initiating a transfer and monitor afterwards.

[11:4] STATUS_HEADER RO 0x00

The status header sent by the ADC.(compatible with AD7768/AD7768-4/AD777x).

[2] PN_ERR RW1C 0x0

PN errors. If set, indicates spurious mismatches in sync state. This bit is cleared if OOS is set and is only indicates errors when OOS is cleared.

[1] PN_OOS RW1C 0x0

PN Out Of Sync. If set, indicates an OOS status. OOS is set, if 64 consecutive patterns mismatch from the expected pattern. It is cleared, when 16 consecutive patterns match the expected pattern.

[0] OVER_RANGE RW1C 0x0

If set, indicates over range. Note that over range is independent of the data path, it indicates an over range over a data transfer period. Software must first clear this bit before initiating a transfer and monitor afterwards.

0x102 + 0x16*n 0x408 + 0x58*n CHAN_RAW_DATAn

ADC Raw Data Reading Where n is from 0 to 15.

[31:0] ADC_READ_DATA RO 0x00000000

Raw data read from the ADC.

0x104 + 0x16*n 0x410 + 0x58*n CHAN_CNTRLn_1

ADC Interface Control & Status Where n is from 0 to 15.

[31:16] DCFILT_OFFSET RW 0x0000

DC removal (if equipped) offset. This is a 2’s complement number added to the incoming data to remove a known DC offset. NOT-APPLICABLE if DCFILTER_DISABLE is set (0x1).

[15:0] DCFILT_COEFF RW 0x0000

DC removal filter (if equipped) coefficient. The format is 1.1.14 (sign, integer and fractional bits). NOT-APPLICABLE if DCFILTER_DISABLE is set (0x1).

0x105 + 0x16*n 0x414 + 0x58*n CHAN_CNTRLn_2

ADC Interface Control & Status Where n is from 0 to 15.

[31:16] IQCOR_COEFF_1 RW 0x0000

IQ correction (if equipped) coefficient. If scale & offset is implemented, this is the scale value and the format is 1.1.14 (sign, integer and fractional bits). If matrix multiplication is used, this is the channel I coefficient and the format is 1.1.14 (sign, integer and fractional bits). If SCALECORRECTION_ONLY is set, this implements the scale value correction for the current channel with the format 1.1.14 (sign, integer and fractional bits). NOT-APPLICABLE if IQCORRECTION_DISABLE is set (0x1).

[15:0] IQCOR_COEFF_2 RW 0x0000

IQ correction (if equipped) coefficient. If scale & offset is implemented, this is the offset value and the format is 2’s complement. If matrix multiplication is used, this is the channel Q coefficient and the format is 1.1.14 (sign, integer and fractional bits). NOT-APPLICABLE if IQCORRECTION_DISABLE is set (0x1).

0x106 + 0x16*n 0x418 + 0x58*n CHAN_CNTRLn_3

ADC Interface Control & Status Where n is from 0 to 15.

[19:16] ADC_PN_SEL RW 0x0

Selects the PN monitor sequence type (available only if ADC supports it).

  • 0x0: pn9a (device specific, modified pn9)

  • 0x1: pn23a (device specific, modified pn23)

  • 0x4: pn7 (standard O.150)

  • 0x5: pn15 (standard O.150)

  • 0x6: pn23 (standard O.150)

  • 0x7: pn31 (standard O.150)

  • 0x9: pnX (device specific, e.g. ad9361)

  • 0x0A: Nibble ramp (Device specific e.g. adrv9001)

  • 0x0B: 16 bit ramp (Device specific e.g. adrv9001)

[3:0] ADC_DATA_SEL RW 0x0

Selects the data source to DMA. 0x0: input data (ADC) 0x1: loopback data (DAC)

0x108 + 0x16*n 0x420 + 0x58*n CHAN_USR_CNTRLn_1

ADC Interface Control & Status Where n is from 0 to 15.

[25] USR_DATATYPE_BE RO 0x0

The user data type format- if set, indicates big endian (default is little endian). NOT-APPLICABLE if USERPORTS_DISABLE is set (0x1).

[24] USR_DATATYPE_SIGNED RO 0x0

The user data type format- if set, indicates signed (2’s complement) data (default is unsigned). NOT-APPLICABLE if USERPORTS_DISABLE is set (0x1).

[23:16] USR_DATATYPE_SHIFT RO 0x00

The user data type format- the amount of right shift for actual samples within the total number of bits. NOT-APPLICABLE if USERPORTS_DISABLE is set (0x1).

[15:8] USR_DATATYPE_TOTAL_BITS RO 0x00

The user data type format- number of total bits used for a sample. The total number of bits must be an integer multiple of 8 (byte aligned). NOT-APPLICABLE if USERPORTS_DISABLE is set (0x1).

[7:0] USR_DATATYPE_BITS RO 0x00

The user data type format- number of bits in a sample. This indicates the actual sample data bits. NOT-APPLICABLE if USERPORTS_DISABLE is set (0x1).

0x109 + 0x16*n 0x424 + 0x58*n CHAN_USR_CNTRLn_2

ADC Interface Control & Status Where n is from 0 to 15.

[31:16] USR_DECIMATION_M RW 0x0000

This holds the user decimation M value of the channel that is currently being selected on the multiplexer above. The total decimation factor is of the form M/N. NOT-APPLICABLE if USERPORTS_DISABLE is set (0x1).

[15:0] USR_DECIMATION_N RW 0x0000

This holds the user decimation N value of the channel that is currently being selected on the multiplexer above. The total decimation factor is of the form M/N. NOT-APPLICABLE if USERPORTS_DISABLE is set (0x1).

0x10a + 0x16*n 0x428 + 0x58*n CHAN_CNTRLn_4

ADC Interface Control & Status Where n is from 0 to 15.

[31:3] RESERVED RO 0x00000000

Reserved for backward compatibility.

[2:0] SOFTSPAN RW 0x7

Softspan configuration register.

DWORD

BYTE

Reg Name

Description

BITS

Field Name

Type

Default Value

Description

0x0 + 0x1*n 0x0 + 0x4*n DELAY_CONTROL_n

Delay Control & Status Where n is from 0 to 15.

[4:0] DELAY_CONTROL_IO_n RW 0x00

Tap value for input/output delay primitive of the n’th interface line. If the delay controller is not locked (indicate issues with delay_clk), the read-back value of this register will be 0xFFFFFFFF. Otherwise will be the last set up value.

Design Guidelines

The control of the AD408x chip is done through a SPI interface, which is needed at system level.

The ADC interface signals must be connected directly to the top file of the design, as I/O primitives are part of the IP.

The example design uses a DMA to move the data from the output of the IP to memory.

If the data needs to be processed in HDL before moving it to the memory, it can be done at the output of the IP (at system level) or inside of the ADC channel module (at IP level).

The example design uses a processor to program all the registers. If no processor is available in your system, you can create your own IP starting from the interface module.

Software Guidelines

Main registers used to control the AXI AD408x IP

Name

Register

BIT

Description

BITSLIP_ENABLE

0x44 (ADC Common)

3

Enables the sync process.

NUM_LANES

0x44 (ADC Common)

[12:8]

Controls the number of lanes enabled.

FILTER_ENABLE

0x4C (ADC Common)

0

Controls the filter status.

SELF_SYNC

0x4C (ADC Common)

1

Controls if the data capture synchronization is done through CNV signal or bit-slip.

SYNC_STATUS

0x68 (ADC Common)

0

States the synchronization status.

Software Suppport

References