General-Purpose Serial Interface
General Purpose Serial Interface, also known as GPSI, 7-wire interface, or 7WS, is a 7 wire communications interface. It is used (designed?) as an interface between Ethernet MAC and PHYS blocks.
Data is received and transmitted using separate data paths (TXD, RXD) and separate data clocks (TXCLK, RXCLK). Other signals consist of transmit enable (TXEN), receive carrier sense (CRS), and collision (COL).
| Signal Name | Direction | Description |
|---|---|---|
| TXD | MAC -> PHYS | Transmit Data (driven on rising edge of TXCLK) |
| TXEN | MAC -> PHYS | Transmit Data Enable (indicates valid TXD) |
| ... etc ... | ... | ... |