Rasp Pi SPI Initial Settings

Disregard that code, that was an I2C test that I have not yet run... Here is the SPI test....

#!/usr/bin/env python3
"""
Test ADAU1467 hardware register read/write
Based on DaveThib's advice from Analog Devices forum
"""
import spidev
import time
import RPi.GPIO as GPIO

RESET_PIN = 26

class ADAU1467:
def __init__(self):
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(RESET_PIN, GPIO.OUT, initial=GPIO.HIGH)

self.spi = spidev.SpiDev()
self.spi.open(0, 0)
self.spi.max_speed_hz = 1000000
self.spi.mode = 0
time.sleep(0.1)

def write_register_16bit(self, addr, value):
"""Write 16-bit value to hardware register"""
addr_high = (addr >> 8) & 0xFF
addr_low = addr & 0xFF
val_high = (value >> 8) & 0xFF
val_low = value & 0xFF

packet = [addr_high, addr_low, val_high, val_low]
self.spi.xfer2(packet)
time.sleep(0.01)

def read_register_16bit(self, addr):
"""Read 16-bit value from hardware register"""
addr_high = ((addr >> 8) & 0xFF) | 0x01 # Set read bit
addr_low = addr & 0xFF

packet = [addr_high, addr_low, 0x00, 0x00]
result = self.spi.xfer2(packet)

# Return 16-bit value from bytes 2 and 3
return (result[2] << 8) | result[3]

def close(self):
self.spi.close()
GPIO.cleanup()

# Test as Dave suggested
print("=" * 60)
print("ADAU1467 Hardware Register Test")
print("Testing register 0xF026 (Clock Gen 3 Input Reference)")
print("=" * 60)

CLOCK_REG = 0xF026

dsp = ADAU1467()

# Step 1: Read default value
print("\nStep 1: Read default value")
default = dsp.read_register_16bit(CLOCK_REG)
print(f" Register 0xF026 = 0x{default:04X} (expected 0x000E)")

# Step 2: Write new value
new_value = 0x0005 # Valid 5-bit value
print(f"\nStep 2: Write new value 0x{new_value:04X}")
dsp.write_register_16bit(CLOCK_REG, new_value)
time.sleep(0.05)

# Step 3: Read back
verify = dsp.read_register_16bit(CLOCK_REG)
print(f" Read back: 0x{verify:04X}")

if verify == new_value:
print("\n✓✓✓ SUCCESS! Hardware register write works!")
else:
print(f"\n✗ Failed (expected 0x{new_value:04X}, got 0x{verify:04X})")

dsp.close()
print("=" * 60)

****And the result....****

============================================================
ADAU1467 Hardware Register Test
Testing register 0xF026 (Clock Gen 3 Input Reference)
============================================================

Step 1: Read default value
Register 0xF026 = 0x00DD (expected 0x000E)

Step 2: Write new value 0x0005
Read back: 0x00DD

✗ Failed (expected 0x0005, got 0x00DD)
============================================================

Hello ElsaDog,

Please note that when the DSP is powered on or comes out of reset, by default the slave control port will be an I2C port, so you have to put it in SPI mode to read/write via SPI.

Please add this code snippet and try again.

If it still doesn't work, please attach your hardware schematic and probe the SPI port and send us the scope shots.

Regards,

Harish

Thanks for the answer, Harish!  It does not seem to change.  I also did an I2C address scan on pins 1 and 3 and see nothing (I am on the  Peripheral Cntl port, J6, btw).  I see SPI echos from the chip when in SPI mode.  Also running MODE 3 per datasheet. Still cant seem to access the registers.  Just FYI, I have a working schematic loaded and it is sending status back to Sig Studio.  When I connect on J1 to the USBi, I see constant updates streaming over the MISO lines on an SPI decode scope.  I was trying to identify the polling protocol but no luck, so far.  The pi is also very particular about seizing the CS line once SPI is running, so I moved it to another GPIO, did the pulse, then moved it back to CE0.  Still no luck.  I am hardware connected MISO on Pi to pin 5, MOSI to pin 8, CLK to pin 7, CEO/SS/CS to pin 9.   Is there a simple handshake code I can execute in the proper format so that I know I have syntax correct?  Thanks!

Thanks for the answer, Harish!  It does not seem to change.  I also did an I2C address scan on pins 1 and 3 and see nothing (I am on the  Peripheral Cntl port, J6, btw).  I see SPI echos from the chip when in SPI mode.  Also running MODE 3 per datasheet. Still cant seem to access the registers.  Just FYI, I have a working schematic loaded and it is sending status back to Sig Studio.  When I connect on J1 to the USBi, I see constant updates streaming over the MISO lines on an SPI decode scope.  I was trying to identify the polling protocol but no luck, so far.  The pi is also very particular about seizing the CS line once SPI is running, so I moved it to another GPIO, did the pulse, then moved it back to CE0.  Still no luck.  I am hardware connected MISO on Pi to pin 5, MOSI to pin 8, CLK to pin 7, CEO/SS/CS to pin 9.   Is there a simple handshake code I can execute in the proper format so that I know I have syntax correct?  Thanks!