ADS1220: SPI Timeout datasheet clarification

Hi Viktorija,

See my responses below.

Best regards,

Bob B

Viktorija Cecil said:

Part Number: ADS1220

Team, 

Please help clarify a few datasheet questions:

1. Section 8.5.1.6 – SPI Timeout:  When the SPI port timeout occurs, what happens to the SPI lines when it resets? BB> Nothing happens on the SPI lines.  The timeout resets an SCLK clock counter internal to the ADS1220.  The timeout would have a similar behavior of toggling the CS lines which also resets the SPI.  The SCLK counter counts the number of clocks received for the desired communication to complete.  All transfers are in byte increments.  Disrupted communication or noise on SCLK can occur which can cause problems when CS is held low permanently.  The SPI timeout allows for communication to be restored.
2. Section 8.5.1.6 – SPI Timeout: After a SPI timeout, how should the host resume communication, and how long does it take for the ADS1220 to reset the SPI port? BB> When the timeout period completes the interface is reset immediately and communication can resume.  If the internal oscillator is used, there can be some variation from part to part, so the timeout period is based on tmod periods and actual time would need to be calculated based on worst case oscillator variation (2%).
3. How long should we wait after the power supply voltage stabilizes before sending the 06h reset command and writing the configuration to the registers? BB> This is a little hard to find, but it is in the datasheet in sections 9.1.6 and 10.1.  Wait at least 50us before attempting to communicate with the ADS1220.

Thanks

Viktorija