SBOS891C October 2018 – September 2023 TMP144
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
Each communication of the SMAART Wire™ / UART protocol consists of 8-bit word, transferred least significant bit (LSB) first. Each 8-bit word begins with a Start bit that is logic low, and ends with a Stop bit that is logic high. By using a Start bit and Stop bit for each 8-bit word, the TMP144 can calibrate each word and keep synchronous communication throughout the process.
The steps for the SMAART Wire™ / UART communication protocol are:
The sequence is shown in Figure 7-4.
The command byte is decoded by the TMP144 to determine the format of the subsequent communication operation. Table 7-2 lists the command register byte values.
COMMAND OPERATION | COMMAND BYTE ENCODING | HEX VALUE | |||||||
---|---|---|---|---|---|---|---|---|---|
C7 (MSB) | C6 | C5 | C4 | C3 | C2 | C1 | C0 (LSB) | ||
GLBL | IN3/ID3 | IN2/ID2 | IN1/ID1 | IN0/ID0 | P1 | P0 | R/W | ||
Global software reset | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 0 | B4 |
Global initialization | 1 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 8C |
Global address assignment | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 90 |
Global clear interrupt | 1 | 0 | 1 | 0 | 1 | 0 | 0 | 1 | A9 |
Global write | 1 | 1 | 1 | 1 | 0 | P1 | P0 | 0 | Based on P[1:0] |
Global read | 1 | 1 | 1 | 1 | 0 | P1 | P0 | 1 | Based on P[1:0] |
Individual write | 0 | ID3 | ID2 | ID1 | ID0 | P1 | P0 | 0 | Based on ID[3:0] and P[1:0] |
Individual read | 0 | ID3 | ID2 | ID1 | ID0 | P1 | P0 | 1 | Based on ID[3:0] and P[1:0] |