PCM2707C: Change descriptor data through SPI

The device descriptor can be modified  through the SPI port (PCM2705C/7C); this descriptor programming function is only available when PSEL and HOST are high as you did. More functional details can be found in  section 9.5.1 USB Interface

Please check the note# 4 (page 35 of datasheet):  MS must be high until the PCM2707C power supply is ready and the SPI host (the DSP) is ready to send data. Also, the SPI host must handle the D+ pullup if the descriptor is programmed through the SPI. D+ pullup must not be activated (high = 3.3 V) before programming of the PCM2707C through the SPI is complete.

Thanks for the reply but this did not resolve my issue.

In the meantime i have been able to change the descriptor name, but it does not work as expected.

Some strange things to make it work:

• Add an extra write at the end (I added a 0x00)
• The first byte of the product string is not used as part of the product string. I should change it everytime i wont to change the descriptor. (it seem to work like an ID or something)

So i am able to change the descriptor but i would like to know how to do it without these weird adjustments 

This is the 'working' code:

static void usb_spiWriteDescriptor()
{
	uint8_t dataToSend[58] = {0xBB, 0x08, 0x04, 0x27,
			0x02, 0x41, 0x75, 0x64, 0x61, 0x63, 0x20, 0x2D, 0x20, 0x44, 0x57, 0x50, 0x33, 0x34, 0x35, 0x20,		// To change this text, the first number needs to be changed
			0x20, 0x20, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x20, 0x61,
			0x72, 0x65, 0x20, 0x70, 0x6C, 0x61, 0x63, 0x65, 0x64, 0x20, 0x68, 0x65, 0x72, 0x65, 0x2E, 0x20,
			0x80,
			0x7D,
			0x0A, 0x93, 0x01, 0x00
		};

	uint8_t wordToSend[2] = {0x02, 0x00};
	spi_DMA_write(0, 0, 2, &wordToSend[0], &usbSPiHandle, GPIO_USBCS);


	/* Reverse the bit order */
	for(uint8_t n = 0; n < 58; n++)
	{
		dataToSend[n] = (dataToSend[n] & 0xF0) >> 4 | (dataToSend[n] & 0x0F) << 4;
		dataToSend[n] = (dataToSend[n] & 0xCC) >> 2 | (dataToSend[n] & 0x33) << 2;
		dataToSend[n] = (dataToSend[n] & 0xAA) >> 1 | (dataToSend[n] & 0x55) << 1;

		wordToSend[1] = dataToSend[n];
		wordToSend[0] = 0x08;

		spi_DMA_write(0, 0, 2, &wordToSend[0], &usbSPiHandle, GPIO_USBCS);
	}
}

I can try to  take a look at your script  but I use  I2C Master type gui , in which  I simply write the instruction for  each register straight in to it  and not familiar with this coding so I might not be able to catch the issue. I will give it a shot though.

Regards,

Arash