DSP Readback is not working

Hello Brian,

To further debug the readback not working issue, the ADAU1452 also supports I²C protocol for programming the device.

The USBi supports both SPI and I²C protocols to program the ADAU1452. However, to use I²C, a few hardware modifications are required on the board. Please follow the steps below:

Step 1: I²C Pull-Up Resistors

Add 2 kΩ pull-up resistors on both SDA and SCL lines:

• MISO / SDA
• SCLK / SCL

The evaluation board does not include these pull-up resistors, so they must be added externally.

Step 2: Slave Address Selection

• The ADDR0 (SS) pin already has a pull-up resistor, so no change is required.
• Connect the ADDR1 pin to GND.

With this configuration, the I²C slave address will be 0x72.

Ensure that the same slave address is selected in the SigmaStudio configuration window.

Please refer to the diagram below for reference.

Step 3: Connection Diagram

Refer to the diagram below for the correct USBi-to-ADAU1452 I²C connection.

You can use jumper wires to make this connection. Just connect the jumper wires between the USBi header and slave control port (add pull up on the I2C lines)

Additionally, I have attached an example SigmaStudio project for reference.
Please apply the required hardware modifications, load the project, and let me know whether the readback functionality works after these changes.

 ADAU1452_I2C_0X72_ADDR.dspproj

We can debug further about why the SPI mode is not working, you are reading all 0xFF, which means the MISO line is sitting high and USBi reads it as all 1's. You can connect the scope on the port and see what's happening. Let's discuss that later, before that let's try with I2C once to verify proper reading between the USBi and the DSP.

Regards 

Harish 

Before I heat up the soldering iron and modify my brand-new hardware from Analog Devices, can anyone verify whether DSP Readback works in the standard USBi SPI mode with the EVAL_ADAU1452REVBZ?

Considering that the hardware correctly functions with SPI to download code to the DSP, including programming the EEPROM, I'm not sure how modifying my hardware to use I2C instead would help. For one thing, I don't believe that I connected the I2C wires on my own PCB, so I would not be able to use the modified USBi (unless I'm missing something).

I need a way to use these hardware tools in the standard mode that they were designed for, and then compare the evaluation board to my custom board. I started with the assumption that Analog Device's own hardware was compatible with each other, and designed my PCB to match. If the AD hardware doesn't work together as provided, then I might have to spin my custom PCB to get things working.

Hello  Brian , 

Yes, the readback works with the standard USBi in SPI mode on the EVAL_ADAU1452REVBZ board. 

On your hardware side, the key objective is to identify the root cause of the issue, which is why I recommended testing the I²C interface. On your evaluation board, the readback functionality does not work over SPI. If the readback works correctly when using I²C, we can confirm that the issue is specific to the SPI interface.

If the readback fails with both SPI and I²C, then it would indicate that the USBi could be the source of the problem.

Additionally, no soldering modifications are required. You can use jumper wires to connect between the USBi header and slave control port (J1), and a breadboard can be used to add the necessary pull-up resistors for the I²C lines.  

This issue is really simple, but we have to figure out what fails in the system.

If your self-boot switch is ON, then turn that OFF and try.

Regards,

Harish

Hello  Brian , 

Yes, the readback works with the standard USBi in SPI mode on the EVAL_ADAU1452REVBZ board. 

On your hardware side, the key objective is to identify the root cause of the issue, which is why I recommended testing the I²C interface. On your evaluation board, the readback functionality does not work over SPI. If the readback works correctly when using I²C, we can confirm that the issue is specific to the SPI interface.

If the readback fails with both SPI and I²C, then it would indicate that the USBi could be the source of the problem.

Additionally, no soldering modifications are required. You can use jumper wires to connect between the USBi header and slave control port (J1), and a breadboard can be used to add the necessary pull-up resistors for the I²C lines.  

This issue is really simple, but we have to figure out what fails in the system.

If your self-boot switch is ON, then turn that OFF and try.

Regards,

Harish