SWRU543B January 2019 – June 2025 CC3230S , CC3230SF , CC3235MODS , CC3235MODSF , CC3235S , CC3235SF
The SPI controller has a built-in 64-byte buffer to unload the DMA or interrupt handler and improve data throughput. This buffer can be used by setting MCSPI_CHCONF[FFER] or MCSPI_CHCONF[FFEW] to 1. The buffer can be used in the following modes:
Two levels, AEL and AFL, in the MCSPI_XFERLEVEL register, rule the buffer management. The driver must set these values as a multiple of SPI word length defined in MCSPI_CHCONF[WL]. The number of bytes written in the FIFO depends on word length (see Table 8-5). The FIFO buffer pointers are reset when the channel is enabled, or when the FIFO configuration changes.
| SPI Word Length | ||
|---|---|---|
| 8 | 16 and 32 | |
| Number of bytes written in the FIFO | 2 bytes | 4 bytes |