The ADS131A0x device operation is controlled and configured through ten commands. Table 13 summarizes the available commands. The commands are stand-alone, 16-bit words and reside in the first device word of the data frame. Write zeroes to the remaining LSBs when operating in either 24-bit or 32-bit word sizes because each command is 16-bits in length. The commands are decoded following the completion of a data frame and take effect immediately. Each recognized command is acknowledged with a status output in the first device word of the next data frame.
|COMMAND||DESCRIPTION||DEVICE WORD||ADDITIONAL DEVICE WORD||COMMAND STATUS RESPONSE|
|STANDBY||Enter low-power standby mode||0022h||ACK = 0022h|
|WAKEUP||Wake-up from standby mode||0033h||ACK = 0033h|
|LOCK||Places the interface in a locked state and ignores all commands except NULL, RREGS, and UNLOCK||0555h||ACK = 0555h|
|UNLOCK||Brings the device out of an unconfigured POR state or a locked state||0655h||ACK = 0655h|
|REGISTER WRITE AND READ COMMANDS|
|RREG||Read a single register at address a aaaa||(001a aaaa 0000 0000)b||REG|
|RREGS||Read (nnnn nnnn + 1) registers starting at address a aaaa||(001a aaaa nnnn nnnn)b||RREGS|
|WREG||Write a single register at address a aaaa with data dddd dddd||(010a aaaa dddd dddd)b||REG (updated register)|
|WREGS||Write (nnnn nnnn + 1) registers beginning at address a aaaa. Additional device words are required to send data (dddd dddd) to register address (a) and data (eeee eeee) to register address (a+1). Each device word contains data for two registers.
The data frame size is extended by (n / 2) device words to allow for command completion.
|(011a aaaa nnnn nnnn)b||(dddd dddd eeee eeee)b||ACK = (010a_aaaa_nnnn_nnnn)b|
A command status response is 16 bits in length, located in the MSBs of the first device word in the DOUT data frame. The response indicates that the command in the previous data frame is executed. When operating in 24-bit or 32-bit word size modes, the remaining LSBs of the command status response device word read back as zero unless Hamming code is used. An example showing the acknowledgment to a user input command is shown in Figure 67.
Some user commands require multiple data words over multiple device frames. This section describes the commands and details which commands require multiple data words.
The command status responses to the user commands are listed in Table 14. Every data frame begins with one of the listed command status responses on DOUT.
|RESPONSE||DESCRIPTION||DEVICE WORD||ADDITIONAL DEVICE WORD|
|READY||Fixed-status word stating that the device is in a power-up ready state or standby mode and is ready for use. The least significant byte of the device word indicates the address 0 hardware device ID code (dd). In the READY state, the device transmits only one word, allowing a 1-word command to be received. An UNLOCK command must be issued before the device responds to other commands.||(FFdd)h||—|
|ACK||Acknowledgment response. The device has received and executed the command and repeats the received command (cccc) as the command status response. (A NULL input does not result in an ACK response).||(cccc)h||—|
|STATUS/REG||Status byte update. Register address a aaaa contains data dddd dddd. This command status response is the response to a recognized RREGS or WREG command.
An automatic status update of register address (02h) is sent when the NULL command is sent.
|(001a aaaa dddd dddd)b||—|
|RREGS||Response for read (nnnn nnnn + 1) registers starting at address a aaaa. Data for two registers are output per device word. If the resulting address extends beyond the usable register space, zeroes are returned for remaining non-existent registers. During an RREGS response, any new input commands are ignored until the RREGS status response completes.||(011a aaaa nnnn nnnn)b||(dddd dddd eeee eeee)b|