SBAS876C August 2018 – June 2019 ADS9224R , ADS9234R
PRODUCTION DATA.
To read a register or write into a register, the host must provide a 16-bit command frame C[15:0] on SDI. A command frame consists of an OPCODE[3:0], ADDRESS[3:0], and DATA[7:0]. The host must keep the CONVST signal high for reading and writing the registers. Figure 70 shows the command frame. Table 9 provides the details of commands for reading and writing registers.
OPCODE[3:0] | DESCRIPTION | ADDRESS[3:0] | DATA[7:0] | |
---|---|---|---|---|
0000 | NOP0 | Command for conversion control and reading conversion results | N/A | N/A |
0001 | WRITE | Command for writing registers | 4-bit register address | 8-bit register data |
0010 | READ(1) | Command for reading registers | 4-bit register address | 00h or FFh |
0101 | Set bit | Command for setting specific bits in a register without changing the other bits | 4-bit register address | Bits with values of 1 in DATA are set and bits with values of 0 in register data are not changed. |
0110 | Clear bit | Command for clearing specific bits in a register without changing the other bits | 4-bit register address | Bits with values of 1 in DATA are cleared and bits with values of 0 in register data are not changed. |
1111 | NOP1 | Command for conversion control and reading conversion results | N/A | N/A |
Remaining combinations | xxxxxxxxx | xxxxxxxxx | Reserved | These commands are reserved and are treated by the device as no operation |