ADS131M08: SPI Read Single Register

Curtis Prehn

Part Number: ADS131M08

Hello,

I'm using a microcontroller to communicate with the ADS131M08. When doing a read register transaction, it seems like the ID register can be read, but other registers seem to be getting what looks like the STATUS register data as a response. I'm not sure what to change. I'm using the ADS131M08EVM and its associated GUI software. I've done a logic analysis of its read register transaction as a reference. The only differences that I can see are in the CS to first/last clock times, baud, and time between the first and second transactions.

I've attached images of the EVM evaluation transactions and the transactions from the MCU I'm using.

Maybe I'm missing something obvious, but I'd appreciate a fresh set of eyes to take a look.

EVM ID Reg Read

MCU ID Reg Read

EVM CLOCK Reg Read

MCU CLOCK Reg Read

Thanks!

over 2 years ago

0 Curtis Prehn over 2 years ago

Intellectual 340 points

I was able to resolve this issue by changing the drive strength value of the chip select line. The logic analyzer likely wasn't picking up the full scope of the problem.

IOMUXC_SetPinConfig(IOMUXC_GPIO1_IO11_GPIO1_IO11, 
                        IOMUXC_SW_PAD_CTL_PAD_DSE(1U) |
                        IOMUXC_SW_PAD_CTL_PAD_FSEL(2U));

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ADS131M08: SPI Read Single Register