SPRUJ53B April 2024 – September 2024 TMS320F28P550SJ , TMS320F28P559SJ-Q1
The multiprocessor communication format allows one processor to efficiently send blocks of data to other processors on the same serial link. On one serial line, there can be only one transfer at a time. In other words, there can be only one talker on a serial line at a time.
Address Byte
The first byte of a block of information that the talker sends contains an address byte that is read by all listeners. Only listeners with the correct address can be interrupted by the data bytes that follow the address byte. The listeners with an incorrect address remain uninterrupted until the next address byte.
Sleep Bit
All processors on the serial link set the SCI SLEEP bit (bit 2 of SCICTL1) to 1 so that the processor is interrupted only when the address byte is detected. When the processor reads a block address that corresponds to the CPU device address as set by your application software, your program must clear the SLEEP bit to enable the SCI to generate an interrupt on receipt of each data byte.
Although the receiver still operates when the SLEEP bit is 1, the receiver does not set RXRDY, RXINT, or any of the receiver error status bits to 1 unless the address byte is detected and the address bit in the received frame is a 1 (applicable to address-bit mode). The SCI does not alter the SLEEP bit; your software must alter the SLEEP bit.