JAJSF44D March 2014 – March 2018 PCM1860 , PCM1861 , PCM1862 , PCM1863 , PCM1864 , PCM1865
PRODUCTION DATA.
All read and write operations for the serial control port use 16-bit data words. Figure 47 shows the control data word format. The most significant bit is the read and write (R/W) bit. For write operations, the bit must be set to 0. For read operations, the bit must be set to 1. There are seven bits, labeled IDX[6:0], that hold the register index (or address) for the read and write operations. The least significant eight bits, D[7:0], contain the data to be written to, or the data that was read from, the register specified by IDX[6:0].
Figure 48 and Figure 49 show the functional timing diagram for writing or reading through the serial control port. MS should be held at logic 1 state until a register needs to be written or read. To start the register write or read cycle, MS should be set to logic 0. Sixteen clocks are then provided on MC, corresponding to the 16 bits of the control data word on MOSI and readback data on MISO. After the eighth clock cycle has completed, the data from the indexed-mode control register appears on MISO during the read operation. After the sixteenth clock cycle has completed, the data is latched into the indexed-mode control register during the write operation. To write or read subsequent data, MS should be set to logic 1 once.
NOTE:
B8 is used for selection of write or read. Setting = 0 indicates a write, while = 1 indicates a read. Bits 15–9 are used for register address. Bits 7–0 are used for register data.