SPRUIY4B February 2023 – May 2024 TMS320F2800152-Q1 , TMS320F2800153-Q1 , TMS320F2800154-Q1 , TMS320F2800155 , TMS320F2800155-Q1 , TMS320F2800156-Q1 , TMS320F2800157 , TMS320F2800157-Q1
To reduce CPU load when receiving a LIN N-byte (with N = 1–8) response in interrupt mode , the SCI/LIN module has eight receive buffers. These buffers can store an entire LIN response in the RDy receive buffers. Figure 23-8 illustrates the receive buffers.
The checksum byte following the data bytes is validated by the internal checksum calculator. The checksum error (CE) flag indicates a checksum error and a CE interrupt is generated if enabled in the SCISETINT register.
The multibuffer 3-bit counter counts the data bytes transferred from the SCIRXSHF register to the RDy receive buffers if multibuffer mode is enabled, or to RD0 if multibuffer mode is disabled. The 3-bit compare register contains the number of data bytes expected to be received. In cases where the ID BYTE field does not convey message length (see Note: Optional Control Length Bits in Section 23.3.1.5), the LENGTH value, indicates the expected length and is used to load the 3-bit compare register. Whether the length control field or the LENGTH value is used is selectable with the COMM MODE bit.
A receive interrupt, and a receive ready RXRDY flag can occur after receiving a response, if there are no response receive errors for the frame (such as, there is no checksum error, frame error, and overrun error). The checksum byte is compared before acknowledging a reception.