SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
The timer module first generates a DMA request on DMA channel 1 when it is enabled. When the first incoming data pattern arrives at the MCRC_PSA_SIGREGL1/H1, the CRC controller will compress it. After one sector of data patterns are compressed, the CRC controller generate a compression complete interrupt. Upon responding to the interrupt the CPU would read from the MCRC_PSA_SECSIGREGL1/H1. It is up to the CPU on how to deal with the PSA value just read. It can compare it to a known signature value or it can write it to another memory location to build a signature file or even transfer the signature out of the device via SCI or SPI. This routine will continue until the entire 2 Mbytes are consumed. The latency of the interrupt response from CPU can cause overrun condition. If CPU does not read from MCRC_PSA_SECSIGREGL1 before the PSA value is overridden with the signature of the next sector of memory, an overrun interrupt will be generated by CRC controller.