ZHCSTD7A December 2021 – November 2023 BQ79631-Q1
PRODUCTION DATA
The frame initialization byte is used in both command and response frames. It is always the first byte of the frame. The frame initialization byte performs two functions. First, it defines the frame as either a command frame (host) or a response frame (device). Second, it defines the length of the frame that follows after the frame initialization byte. This provides the receiver an exact number of bytes to expect for a complete command or response.
Command Frame | Response Frame | ||||
---|---|---|---|---|---|
Bit | Bit Name | Description | Bit Name | Description | |
INIT | 7 | FRAME_TYPE | 1 = Define Command Frame | FRAME_TYPE | 0 = Defines Response Frame |
6 | REQ_TYPE | 000 = Single Device Read 001 = Single Device Write 010 = Stack Read 011 = Stack Write 100 = Broadcast Read 101 = Broadcast Write 110 = Broadcast Write Reverse 111 = RSVD(1) |
RESPONSE_BYTE | Number of the data bytes 0x00 = 1 byte 0x01 = 2 bytes : 0x7F = 128 bytes |
|
5 | |||||
4 | |||||
3 | RSVD | Reserved. This bit is ignored | |||
2 | DATA_SIZE | Number of data bytes of the command frame, excluding
device address, register address or CRC 000 = 1 byte 001 = 2 bytes : 111 = 8 bytes |
|||
1 | |||||
0 |