AXI LTC2387

The AXI LTC2387 IP core can be used to interface LTC2387-18, LTC2386-18, LTC2385-18 and ADAQ23878 devices.

This documentation only covers the IP core and requires that one must 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-based configuration

• Vivado compatible

• High-speed data acquisition

• Imaging

• Communications

• Control loops

• Instrumentation

• ATE

Files

Name	Description
library/axi_ltc2387/axi_ltc2387.v	Verilog source for the module
library/axi_ltc2387/axi_ltc2387_channel.v	Verilog source for AXI LTC2387 channel
library/axi_ltc2387/axi_ltc2387_if.v	Verilog source for the AXI LTC2387 interface module
library/common/up_adc_common.v	Verilog source for the ADC Common regmap
library/common/up_adc_channel.v	Verilog source for the ADC Channel regmap

Block Diagram

Configuration Parameters

Name	Description	Default Value	Choices/Range
ID	Id.	0
FPGA_TECHNOLOGY	Fpga Technology.	1
FPGA_FAMILY	Fpga Family.	1
SPEED_GRADE	Speed Grade.	1
DEV_PACKAGE	Dev Package.	1
IO_DELAY_GROUP	Io Delay Group.	adc_if_delay_group
IODELAY_CTRL	Iodelay Ctrl.	1
DELAY_REFCLK_FREQUENCY	Delay Refclk Frequency.	200
USERPORTS_DISABLE	Userports Disable.	0
DATAFORMAT_DISABLE	Dataformat Disable.	0
ADC_INIT_DELAY	Adc Init Delay.	22
ADC_RES	ADC_RES.	18	18, 16
OUT_RES	OUT_RES.	32	32, 16
TWOLANES	Twolanes.	1	1, 0

Interface

s_axi

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

s_axi_aclk

Physical Port	Logical Port	Direction	Dependency
s_axi_aclk	CLK	in

s_axi_aresetn

Physical Port	Logical Port	Direction	Dependency
s_axi_aresetn	RST	in

ref_clk

Physical Port	Logical Port	Direction	Dependency
ref_clk	CLK	in

dco_p

Physical Port	Logical Port	Direction	Dependency
dco_p	CLK	in

dco_n

Physical Port	Logical Port	Direction	Dependency
dco_n	CLK	in

Ports

Physical Port	Direction	Dependency	Description
delay_clk	in
clk_gate	in
da_p	in
da_n	in
db_p	in
db_n	in
adc_valid	out
adc_data	out [31:0]
adc_dovf	in

Detailed Architecture

From the HDL perspective, the selection between the 16-bit and the 18-bit version of the chip, is done by the ADC_RES and OUT_RES parameters of the modules.

• For the 18-bit, ADC_RES=18 (=> OUT_RES=32; addresses should be on a nb. of bits power of 2)

• For the 16-bit, ADC_RES=16 (=> OUT_RES=16)

Warning

When using the ONE LANE configuration (TWOLANES=0), the only resolution supported is 18 bits!

Detailed Description

The top module instantiates:

• the (LVDS) interface module

• the channel processing module

• the delay control module

• the ADC common register map

• the AXI handling interface

Interface module description

The LVDS interface module has as inputs the LVDS signals for clock and data:

• dco_p/dco_n: LVDS clock input; it is an echoed version of the CLK+/CLK- signal, and it’s used to latch the data outputs from the chip.

• da_p/da_n and db_p/db_n: serial LVDS data inputs; DB+/- is used only when TWOLANES=1

• clk_gate: this signal clk_gate is enabling the CLK+/CLK- which is driven by the reference clock. It is generated by AXI_PWM_GEN.

• adc_valid: it is 1 for the current sample that is sent. This is generated depending on clk_gate.

• adc_data: depending on TWOLANES parameter, whether it is set or not, the output adc_data is either taken from the da_p/_n port interleaved with bits from db_p/_n, or it is taken only from da_p/_n port.

Channel module description

The expected pattern is created and checked if the data received from the DMA is the correct one (this is used for quick validation of the design).

In the case of the device with 16-bit resolution, a sign extension is done additionally.

Register Map

Base (common to all cores) register map

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
		[0:0]	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)
		[1:1]	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)
		[2:2]	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)
		[3:3]	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)
		[4:4]	MODE_1R1T	RO	0x0	If set, indicates that the core was implemented in 1 channel mode. (e.g. refer to AD9361 data sheet)
		[5:5]	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)
		[6:6]	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)
		[7:7]	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)
		[8:8]	PPS_RECEIVER_ENABLE	RO	0x0	If set, indicates the PPS receiver is enabled. (as a result of a configuration of the IP instance)
		[9:9]	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)
		[12:12]	EXT_SYNC	RO	0x0	If set the transport layer cores (ADC/DAC) have implemented the support for external synchronization signal.
		[13:13]	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
		[0:0]	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

ADC Common (axi_ad*) register map

DWORD	BYTE	Reg Name				Description
		BITS	Field Name	Type	Default Value	Description
0x10	0x40	RSTN				ADC Interface Control & Status
		[2:2]	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
		[1:1]	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.
		[0:0]	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
		[16:16]	SDR_DDR_N	RW	0x0	Interface type (1 represents SDR, 0 represents DDR)
		[15:15]	SYMB_OP	RW	0x0	Select symbol data format mode (0x1)
		[14:14]	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.
		[3:3]	SYNC	RW	0x0	Initialize synchronization between multiple ADCs
		[2:2]	R1_MODE	RW	0x0	Select number of RF channels 1 (0x1) or 2 (0x0).
		[1:1]	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.
		[0:0]	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
		[1:1]	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.
		[2:2]	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.
		[8:8]	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
		[8:8]	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
		[4:4]	ADC_CTRL_STATUS	RO	0x0	If set, indicates that the device’​s register data is available on the data bus.
		[3:3]	PN_ERR	RO	0x0	If set, indicates pn error in one or more channels.
		[2:2]	PN_OOS	RO	0x0	If set, indicates pn oos in one or more channels.
		[1:1]	OVER_RANGE	RO	0x0	If set, indicates over range in one or more channels.
		[0:0]	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)
		[17:17]	DELAY_SEL	RW	0x0	Delay select, a 0x0 to 0x1 transition in this register initiates a delay access controlled by the registers below.
		[16:16]	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)
		[9:9]	DELAY_LOCKED	RO	0x0	Indicates delay locked (0x1) state. If this bit is read 0x0, delay control has failed to calibrate the elements.
		[8:8]	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
		[0:0]	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
		[28:28]	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
		[17:17]	DRP_LOCKED	RO	0x0	If set indicates that the DRP has been locked.
		[16:16]	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
		[2:2]	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.
		[1:1]	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.
		[0:0]	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
		[0:0]	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.

ADC Channel (axi_ad*) register map

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.
		[11:11]	ADC_LB_OWR	RW	0x0	If set, forces ADC_DATA_SEL to 1, enabling data loopback
		[10:10]	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
		[9:9]	IQCOR_ENB	RW	0x0	if set, enables IQ correction or scale correction. NOT-APPLICABLE if IQCORRECTION_DISABLE is set (0x1).
		[8:8]	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).
		[6:6]	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).
		[5:5]	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).
		[4:4]	FORMAT_ENABLE	RW	0x0	Enable data format conversion (see register bits above). NOT-APPLICABLE if DATAFORMAT_DISABLE is set (0x1).
		[3:3]	RESERVED	RO	0x0	Reserved for backward compatibility.
		[2:2]	RESERVED	RO	0x0	Reserved for backward compatibility.
		[1:1]	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
		[0:0]	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.
		[12:12]	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).
		[2:2]	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.
		[1:1]	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.
		[0:0]	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.
		[25:25]	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).
		[24:24]	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.

Design Guidelines

The control of the chip is done through an SPI interface, which is needed at the system level. The Interface 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 to the memory, it can be done at the output of the IP (at the system level) or inside the ADC interface module (at the 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 IP starting from the interface module.

Software Support

• Linux device driver at drivers/iio/adc/ltc2387.c

• LTC2387 Linux device tree at arch/arm/boot/dts/zynq-zed-adv7511-ltc2387.dts

• CN0577 Linux device tree at arch/arm/boot/dts/zynq-zed-adv7511-cn0577.dts

• Linux documentation at [Wiki]

References

• HDL IP core at library/axi_ltc2387

• HDL project at projects/cn0577

• HDL project documentation at CN0577 HDL project

• LTC2387-18 18-bit 15 MSPS

• LTC2386-18 18-bit 10 MSPS

• LTC2385-18 18-bit 5 MSPS

• ADAQ23878 18-bit 15 MSPS

• Zynq-7000 SoC Overview.

• Zynq-7000 SoC Packaging and Pinout.