The SDI input data word is 2 bytes long and
consists of the following format:
- Command byte (first byte)
- MSB bit indicates frame type (bit
B15 = 0 for standard frame).
- Next to MSB bit, W0, indicates read
or write operation (bit B14, write = 0, read = 1)
- Followed by 6 address bits, A[5:0]
(bits B13 through B8)
- Data byte (second byte)
- Second byte indicates data, D[7:0]
(bits B7 through B0). For a read operation, these bits are typically set to null
values, while for a write operation, these bits have the data value for the
addressed register.
Table 8-20 SDI - Standard Frame Format
|
Command Byte |
Data Byte |
Bit |
B15 |
B14 |
B13 |
B12 |
B11 |
B10 |
B9 |
B8 |
B7 |
B6 |
B5 |
B4 |
B3 |
B2 |
B1 |
B0 |
Data |
0 |
W0 |
A5 |
A4 |
A3 |
A2 |
A1 |
A0 |
D7 |
D6 |
D5 |
D4 |
D3 |
D2 |
D1 |
D0 |
The SDO output data word is 2 bytes long and
consists of the following format:
- Status byte (first byte)
- 2 MSB bits are forced high (B15,
B14 = 1)
- Following 6 bits are from the FAULT
SUMMARY register (B13:B8)
- Report byte (second byte)
- The second byte (B7:B0) is either
the data currently in the register being read for a read operation (W0 = 1), or,
existing data in the register being written to for a write command (W0 = 0)
Table 8-21 SDO - Standard Frame Format | Status Byte | Report Byte |
---|
Bit | B15 | B14 | B13 | B12 | B11 | B10 | B9 | B8 | B7 | B6 | B5 | B4 | B3 | B2 | B1 | B0 |
Data | 1 | 1 | FAULT | VMOV | VMUV | OCP | TSD | SPI_ERR | D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 |