Visible to Intel only — GUID: nik1409872339101
Ixiasoft
Visible to Intel only — GUID: nik1409872339101
Ixiasoft
2.2.2. Transmitter Clocking
The following figure shows how the clock divider provides the serial clock to the serializer, and the parallel clock to the serializer and TX PCS. When the byte serializer is not used, the parallel clock is used to clock all the blocks up to the read side of the TX phase compensation FIFO. For configurations with the byte serializer, the parallel clock is divided by a factor of two for the byte serializer and the read side of the TX phase compensation FIFO. The read side clock of the TX phase compensation FIFO is also forwarded to the FPGA fabric to interface the FPGA fabric with the transceiver.
PCS Block | Side | Clock Source |
---|---|---|
TX Phase Compensation FIFO | Write | FPGA fabric write clock, driven either by tx_clkout or tx_coreclkin |
Read | Parallel clock (divided). Clock forwarded to FPGA fabric as tx_clkout | |
Byte Serializer | Write | Parallel clock (divided) either by factor of 1 (not enabled), or factor of 2 (enabled) |
Read | Parallel clock | |
8B/10B Encoder | — | Parallel clock |
TX Bit Slip | — | Parallel clock |
The following figure shows how the clock divider provides the serial and parallel clock to the serializer in a transmitter PMA configuration. The parallel clock is forwarded to the FPGA fabric to interface the FPGA fabric with the TX PMA directly, bypassing the PCS blocks.
Transmitter 10G PCS Clocking for GZ Devices
The following figure shows the clocking scheme for the transmitter 10G PCS and transmitter physical medium attachment (PMA). The clock divider block provides the serial clock to the serializer of the transmitter PMA and the parallel clock to the transmitter PCS. In the 10G PCS channel, the parallel clock is used by all the blocks up to the read side of the transmitter (TX) FIFO.