JAJSGF2C August 2012 – October 2018 PCM5121 , PCM5122
PRODUCTION DATA.
All read/write operations for the serial control port use 16-bit data words. Figure 66 shows the control data word format. The most significant bit is the read/write 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 66 and Figure 67 show the functional timing diagram to write or read through the serial control port. MS is held at a logic-1 state until a register access. To start the register write or read cycle, set MS to logic 0. Sixteen clocks are then provided on MC, corresponding to the 16 bits of the control data word on MOSI and read-back 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 is set to logic 1 once (see tMHH in Figure 71).
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. Multiple-byte write or read (up to 8 bytes) is supported while MS is kept low. The address field becomes the initial address, automatically incrementing for each byte.
MIN | MAX | UNIT | ||
---|---|---|---|---|
tMCY | MC Pulse Cycle Time | 100 | ns | |
tMCL | MC Low Level Time | 40 | ns | |
tMCH | MC High Level Time | 40 | ns | |
tMHH | MS High Level Time | 20 | ns | |
tMSS | MS ↓ Edge to MC ↑ Edge | 30 | ns | |
tMSH | MS Hold Time(1) | 30 | ns | |
tMDH | MDI Hold Time | 15 | ns | |
tMDS | MDI Set-up Time | 15 | ns | |
tMOS | MC Rise Edge to MDO Stable | 20 | ns |