Visible to Intel only — GUID: nik1411172664195
Ixiasoft
Visible to Intel only — GUID: nik1411172664195
Ixiasoft
3.4.2.3. 2‑Wire Serial Interface Registers
Several optical modules use the 2‑wire serial interface protocol, which requires only limited resources. This interface uses two, bidirectional open‑drain lines, a serial data line (SDA) and a serial clock (SCL). The master node drives the clock and addresses slaves. Data is sent most significant bit first. The slave node receives the clock and address. Unlike the MDIO protocol, the 2-wire serial interface can include multiple masters. In addition, the master and slave roles may be changed after a STOP message is sent. The interface has an eight‑bit address space, so a maximum of 255 nodes can communicate. The interface runs at 400 KHz.
Address |
Name |
Bits |
Description |
HW Reset Value |
Access |
---|---|---|---|---|---|
0x420 |
2WS_WDATA |
[7:0] |
Data to be written. |
0x00 |
RW |
0x421 |
2WS_RDATA |
[31] |
When asserted, the link is busy. |
1b’0 |
R |
[30] |
When asserted, indicates that the slave failed to acknowledge during the previous operation. |
1b’0 |
R |
||
[7:0] |
Result of previous read. |
0x00 |
R |
||
0x422 |
2WS_ADDR |
[15:8] |
Slave address. |
0xA0 |
RW |
[7:0] |
Memory address. |
0x00 |
RW |
||
0x423 |
2WS_CMD |
[1] |
When asserted, indicates a write command. |
0x0 |
RW |
[0] |
When asserted, indicates a read. |
0x0 |
RW |