For further programmability, the TUSB564 can be controlled using I2C. The SCL and SDA pins are used for I2C clock and I2C data respectively.
Table 8-9 TUSB564 I2C Target AddressDPEQ0/A1
PIN LEVEL | SSEQ0/A0
PIN LEVEL | Bit 7 (MSB) | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 (W/R) |
|---|
| 0 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0/1 |
| 0 | R | 1 | 0 | 0 | 0 | 1 | 0 | 1 | 0/1 |
| 0 | F | 1 | 0 | 0 | 0 | 1 | 1 | 0 | 0/1 |
| 0 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 0/1 |
| R | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0/1 |
| R | R | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0/1 |
| R | F | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 0/1 |
| R | 1 | 0 | 1 | 0 | 0 | 0 | 1 | 1 | 0/1 |
| F | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0/1 |
| F | R | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 0/1 |
| F | F | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 0/1 |
| F | 1 | 0 | 0 | 1 | 0 | 0 | 1 | 1 | 0/1 |
| 1 | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 0/1 |
| 1 | R | 0 | 0 | 0 | 1 | 1 | 0 | 1 | 0/1 |
| 1 | F | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 0/1 |
| 1 | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 0/1 |
The following procedure should be followed to write to TUSB564 I2C registers:
- The controller initiates a write operation by generating a start condition (S), followed by the TUSB564 7-bit address and a zero-value “W/R” bit to indicate a write cycle.
- The TUSB564 acknowledges the address cycle.
- The controller presents the sub-address (I2C register within TUSB564) to be written, consisting of one byte of data, MSB-first.
- The TUSB564 acknowledges the sub-address cycle.
- The controller presents the first byte of data to be written to the I2C register.
- The TUSB564 acknowledges the byte transfer.
- The controller may continue presenting additional bytes of data to be written, with each byte transfer completing with an acknowledge from the TUSB564.
- The controller terminates the write operation by generating a stop condition (P).
The following procedure should be followed to read the TUSB564 I2C registers:
- The controller initiates a read operation by generating a start condition (S), followed by the TUSB564 7-bit address and a one-value “W/R” bit to indicate a read cycle.
- The TUSB564 acknowledges the address cycle.
- The TUSB564 transmit the contents of the memory registers MSB-first starting at register 00h or last read sub-address+1. If a write to the I2C register occurred prior to the read, then the TUSB564 shall start at the sub-address specified in the write.
- The TUSB564 shall wait for either an acknowledge (ACK) or a not-acknowledge (NACK) from the controller after each byte transfer; the I2C controller acknowledges reception of each data byte transfer.
- If an ACK is received, the TUSB564 transmits the next byte of data.
- The controller terminates the read operation by generating a stop condition (P).
The following procedure should be followed for setting a starting sub-address for I2C reads:
- The controller initiates a write operation by generating a start condition (S), followed by the TUSB564 7-bit address and a zero-value “W/R” bit to indicate a write cycle.
- The TUSB564 acknowledges the address cycle.
- The controller presents the sub-address (I2C register within TUSB564) to be written, consisting of one byte of data, MSB-first.
- The TUSB564 acknowledges the sub-address cycle.
- The controller terminates the write operation by generating a stop condition (P).
Note: If no sub-addressing is included for the read procedure, and reads start at register offset 00h and continue byte by byte through the registers until the I2C controller terminates the read operation. If a I2C address write occurred prior to the read, then the reads start at the sub-address specified by the address write.
Table 8-10 Register Legend| ACCESS TAG | NAME | MEANING |
|---|
| R | Read | The field may be read by software |
| W | Write | The field may be written by software |
| S | Set | The field may be set by a write of one. Writes of zeros to the field have no effect. |
| C | Clear | The field may be cleared by a write of one. Write of zero to the field have no effect. |
| U | Update | Hardware may autonomously update this field. |
| NA | No Access | Not accessible or not applicable |