SBASAM0B March 2024 – November 2024 ADS127L18
PRODMIX
Commands are used to read and write register data to configure and control the device. Commands are two bytes long (plus an optional CRC byte). The Register Map is a series of 8-bit registers, accessible by read and write operations, one register access at a time. When SPI CRC is enabled, the device computes the CRC input value of the two bytes preceding the CRC byte to verify the command. Table 7-18 shows the command format.
COMMAND | BYTE1 | BYTE2 | BYTE 3 (Optional CRC Mode) |
---|---|---|---|
Read register | 00h + register address [6:0] | Don't care | CRC of byte 1 and byte 2 |
Write register | 80h + register address [6:0] | Register data | CRC of byte 1 and byte 2 |
There is a special input bit pattern that directly resets the ADC. See the Reset by SPI Input Pattern section for details.
Table 7-19 summarizes the input and output byte sequence for read and write commands corresponding to the STATUS and CRC options. STATUS and CRC are enabled by setting the respective bits in the GEN_CFG3 register. The communication frame size is 2 or 3 bytes depending if CRC is enabled.
FRAME SIZE | STATUS | CRC | INPUT BYTE SEQUENCE | OUTPUT BYTE SEQUENCE(1) |
---|---|---|---|---|
2 bytes | no | no | Write Command: Command + Data Read Command: Command + 0 |
Write Command: ECHO + 0 Read Command: Data + 0 |
yes | no | Write Command: ECHO + STATUS Read Command: Data + STATUS |
||
3 bytes | no | yes | Write Command: Command + Data +
CRC Read Command: Command + 0 + CRC |
Write Command: ECHO+ 0 + CRC Read Command: Data + 0 + CRC |
yes | yes | Write Command: ECHO + STATUS + CRC Read Command: Data + STATUS + CRC |