AD7616-SDZ HDL project

Overview

The AD7616 is a 16-bit, data acquisition system (DAS) that supports dual simultaneous sampling of 16 channels. It operates from a single 5 V supply and can accommodate ±10 V, ±5 V, and ±2.5 V true bipolar input signals while sampling at throughput rates up to 1 MSPS per channel pair with 90 dB SNR. Higher SNR performance can be achieved with the on-chip oversampling mode; 92 dB for an oversampling ratio of 2.

The input clamp protection circuitry can tolerate voltages up to ±20 V. The AD7616 has 1 MΩ analog input impedance regardless of sampling frequency. The single supply operation, on-chip filtering, and high input impedance eliminate the need for driver op-amps and external bipolar supplies.

Each device contains analog input clamp protection, a dual, 16-bit charge redistribution successive approximation analog-to-digital converter (ADC), a flexible digital filter, a 2.5 V reference and reference buffer, and high-speed serial and parallel interfaces.

Supported boards

Supported devices

Supported carriers

Other required hardware

Block design

The data path of the HDL design is simple as follows:

  • the parallel interface is controlled by the axi_ad7616 IP core

  • the serial interface is controlled by the SPI_Engine Framework

  • data is written into memory by a DMA (axi_dmac core)

  • all the control pins of the device are driven by GPIOs

Block diagram

The data path and clock domains are depicted in the below diagrams:

AD7616_SDZ serial interface

AD7616_SDZ using the serial interface block diagram

AD7616_SDZ parallel interface

AD7616_SDZ using the parallel interface block diagram

Configuration modes

The INTF configuration parameter defines the interface type (Serial or Parallel). By default it is set to Parallel (0). Depending on the required interface mode, some hardware modifications need to be done on the board and/or make command:

In case of the PARALLEL interface:

~$

make INTF=0

In case of the SERIAL interface:

~$

make INTF=1

Note

This switch is a hardware switch. Please rebuild the design if the variable has been changed.

  • SL5 - unmounted - Parallel interface

  • SL5 - mounted - Serial interface

Jumper setup

Jumper/Solder link

Position

Description

SL1

Unmounted

Channel Sequencer Enable

SL2

Unmounted

RC Enable Input

SL3

Mounted

Selects 2 MISO mode

SL4

Unmounted

Oversampling Ratio Selection OS2

SL5

Mounted

If mounted, selects serial interface

SL6

Unmounted

Oversampling Ratio Selection OS1

SL7

Unmounted

Oversampling Ratio Selection OS0

LK40

A

Onboard 5v0 power supply selected

LK41

A

Onboard 3v3 power supply selected

CPU/Memory interconnects addresses

The addresses are dependent on the architecture of the FPGA, having an offset added to the base address from HDL(see more at CPU/Memory interconnects addresses).

Instance

Zynq

axi_ad7616_dma

0x44A3_0000

ad7616_pwm_gen

0x44B0_0000

spi_ad7616_axi_regmap **

0x44A0_0000

axi_ad7616 *

0x44A8_0000

Legend

  • * instantiated only for INTF=0 (parallel interface)

  • ** instantiated only for INTF=1 (serial interface)

I2C connections

I2C type

I2C manager instance

Alias

Address

I2C subordinate

PL

iic_fmc

axi_iic_fmc

0x4162_0000

—

PL

iic_main

axi_iic_main

0x4160_0000

—

SPI connections

SPI type

SPI manager instance

SPI subordinate

CS

PL

axi_spi_engine

AD7616

0

GPIOs

The Software GPIO number is calculated as follows:

  • Zynq-7000: if PS7 is used, then offset is 54

GPIO signal

Direction

HDL GPIO EMIO

Software GPIO

(from FPGA view)

Zynq-7000

adc_reset_n

OUT

43

97

adc_hw_rngsel[1:0]

OUT

42:41

96:95

adc_os[2:0] **

OUT

40:38

94:92

adc_seq_en

OUT

37

91

adc_burst **

OUT

36

90

adc_chsel[2:0]

OUT

35:33

89:87

adc_crcen **

OUT

32

86

Legend

  • ** instantiated only for INTF=1 (serial interface)

Interrupts

Below are the Programmable Logic interrupts used in this project.

Instance name

HDL

Linux Zynq

Actual Zynq

axi_ad7616_dma

13

57

89

spi_ad7616 **

12

56

88

axi_ad7616 *

10

54

87

Legend

  • * instantiated only for INTF=0 (parallel interface)

  • ** instantiated only for INTF=1 (serial interface)

Building the HDL project

The design is built upon ADI’s generic HDL reference design framework. ADI distributes the bit/elf files of these projects as part of the ADI Kuiper Linux. If you want to build the sources, ADI makes them available on the HDL repository. To get the source you must clone the HDL repository, and then build the project as follows:.

Linux/Cygwin/WSL

~$

cd hdl/projects/ad7616_sdz/zed

~/hdl/projects/ad7616_sdz/zed$

make INTF=0

The default configuration is Parallel Mode (0).

The result of the build, if parameters were used, will be in a folder named by the configuration used:

if the following command was run

make INTF=0

then the folder name will be:

INTF0

A more comprehensive build guide can be found in the Build an HDL project user guide.

Connections and hardware changes

Warning

The following hardware changes are required:

(Please note: Because of the SDP-I-FMC the level of the VADJ in the carrier board needs to be set to 3.3V.)

Depending on the required interface mode, some hardware modifications need to be done.

  • SL5 - unmounted - Parallel interface

  • SL5 - mounted - Serial interface

Resources

More information

Support

Analog Devices, Inc. will provide limited online support for anyone using the reference design with ADI components via the EngineerZone FPGA reference designs forum.

For questions regarding the ADI Linux device drivers, device trees, etc. from our Linux GitHub repository, the team will offer support on the EngineerZone Linux software drivers forum.

For questions concerning the ADI No-OS drivers, from our No-OS GitHub repository, the team will offer support on the EngineerZone microcontroller No-OS drivers forum.

It should be noted, that the older the tools’ versions and release branches are, the lower the chances to receive support from ADI engineers.