Other Parts Discussed in Thread: ADS1278, TMS320F28388S
Hello everyone,
We're considering to develop a data acquisition system based on ADS1274, and been looking for SoCs to process the data. The plan is to fully exploit the ADC capabilities, so initially we're designing to use 4 channels in either TDM or discrete mode. We're also considering to make the system compatible with ADS1278, so we're looking at the possibility of reading 8 channels as well.
Looking for a platform to handle and process the data, the C2000 family caught our attention since we need real time processing. Currently planning to work with tms320f28388s and communicating both devices through SPI, some issues arise.
The main one is the data transfer rate. In tms320f28388s' datasheet it is specified that SPI ... allows a serial bit stream of programmed length (1 to 16 bits) to be shifted into and out of the device at a programmed bit-transfer rate. Since each channel of the ADS1274 produces 24 bits of data, we'll need to handle without interruption transfers of 96 bits int TDM mode or 24 through 4 separate SPI ports.
- Would the hardware's SPI be able to handle the 24 bit data despite its maximum 16 bit word size?
- If not, should we look for microcontrollers able to handle 32 bit words via SPI, or it is possible to control the data transfer through software without losing data? (mostly worried about the possibility of not being able to read without interruption).
- The same questions could apply for a TDM configuration, where a single SPI port would to read 96 bits.
Now some side issues, about the other possible ports we've considered:
- Regarding the possibility of using ADS1278, tms320f28388s offers 8 FSI ports with SPI signaling mode, but has the same word limitation than SPI ports, so we face the same issues with these.
- We've been also considering using McBSP in TDM mode since it's able to handle 24 data size, but reading the port documentation we've understood it requires to enable clock stop mode to separate frames. Before getting deep into the port, will it be able to read the 96 bits (or 192 if using ADS1278) without losing data?
Thanks for your time,
Manuel Soler.
