SCAS928D May 2012 – April 2019 CDCUN1208LP
PRODUCTION DATA.
A SPI communication link includes a master and one or more slaves (note that CDCUN1208LP supports only single-device). Table 8 lists the four signal lines that form a SPI communication link. Figure 32 shows the format for SPI messages. The SPI master (host) initiates communication by asserting SCS low. Information on SDI/SDO is latched on each rising edge of SCL. The first bit transmitted on SDI establishes the direction of the SPI transfer. Next, the master transmits the address to be written/read (up to 15 bits). If the operation is a write, the master transmits 16 data bits on SDI. If the transfer is a read, the slave transmits 16 data bits on SDO (the master continues to clock the transfer through SCL). Figure 34 and Table 9 show the timing specifications for SPI.