SPRUIY4B February 2023 – May 2024 TMS320F2800152-Q1 , TMS320F2800153-Q1 , TMS320F2800154-Q1 , TMS320F2800155 , TMS320F2800155-Q1 , TMS320F2800156-Q1 , TMS320F2800157 , TMS320F2800157-Q1
To reduce the CPU load when transmitting a LIN N-byte (with N = 1–8) response in interrupt mode , the SCI/LIN module has 8 transmit buffers, TD0–TD7 in LINTD0 and LINTD1. With these transmit buffers, an entire LIN response field can be preloaded in the TXy transmit buffers. Figure 23-9 illustrates the transmit buffers.
The multibuffer 3-bit counter counts the data bytes transferred from the TDy transmit buffers register if multibuffer mode is enabled, or from TD0 to SCITXSHF if multibuffer mode is disabled. The 3-bit compare register contains the number of data bytes expected to be transmitted. If the ID field is not used to 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 instead 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 transmit interrupt (TX interrupt) and a transmit ready flag (TXRDY flag) can occur after transmitting a response.
The checksum byte is automatically generated by the checksum calculator and sent after the data-fields transmission is finished. The multibuffer 3-bit counter counts the data bytes transferred from the TDy buffers into the SCITXSHF register.