Visible to Intel only — GUID: svu1488565691869
Ixiasoft
Visible to Intel only — GUID: svu1488565691869
Ixiasoft
51.3.2. Clock Scheme
During GMII mode (1000 Mbps), both the HPS and PCS blocks generate a transmit clock. The GMII/MII data from the HPS is synchronous to the HPS’s internal PLL while the PCS block expects transmit data to be synchronous to its own transmit clock. To solve two different transmit clocks in a transmit data path, an elastic buffer is used for transmit data transmission.
During MII mode (10/100 Mbps), a transmit clock only comes from the PCS block. The transmit clock connected to the HPS is the gated version of transmit clock sent from PCS block with the worst duty cycle of 1% (high: 4 ns, low: 396 ns).
The receive clock comes from the PCS block. The receive clock connected to the HPS is the gated version of receive clock sent from the PCS block with worst duty cycle of 1% (high: 4 ns, low: 396 ns).