Visible to Intel only — GUID: ndz1681940379908
Ixiasoft
Visible to Intel only — GUID: ndz1681940379908
Ixiasoft
3.5. Bit Mapping for PMA and FEC Mode PHY TX and RX Datapath
The tx_parallel_data bit and rx_parallel_data bit width depends on the PMA width and Number of PMA lanes IP parameters. Use the following equation to determine the total tx_parallel_data or rx_parallel_data bit width:
Total tx_parallel_data or rx_parallel_data Bit Width Equation:
tx/rx_parallel_data[(80*N)-1:0]
Where:
- N = Number of PMA lanes value from 1 to 4.
The tx/rx_parallel_data signals include the valid parallel data bits and other functionality bits, such as the data valid bit, the write enable for TX core interface FIFO in elastic mode bit, the RX deskew bit, and the alignment marker bits (for FEC mode). These signals travel to and from the FPGA fabric to the transceiver block, and are clocked by the same parallel clock. This parallel clock can be a PMA clock or System PLL clock.
Example 1: Total tx/rx_parallel_data Bit Width with 2 PMA Lanes (N=2) and 8-bit PMA Width (X=1)
tx_parallel_data [(80*2)-1:0] = tx_parallel_data [159:0] rx_parallel_data [(80*2)-1:0] = rx_parallel_data [159:0]
Parallel Data Mapping information for TX and RX
Variable | Values | Description |
---|---|---|
N | 1, 2, 4, 6, 8 | Number of lanes |
n | 0 to N-1 | N is the PMA index number |
D | D = PMA Width | D is the data width value to calculate the total parallel data bits |
PMA Configuration | MSB | LSB | TX Parallel Data | RX Parallel Data |
---|---|---|---|---|
PMA Width = 8, 10, 16, 20, 32 Single Width |
79 | Write Enable for TX Core FIFO in Elastic Mode 29 | Data valid for RX Core FIFO in Elastic Mode29 | |
38 + (80*n) | TX PMA Interface Data Valid | RX PMA Interface Data Valid | ||
[D-1] + (80*n) | 0 + (80*n) | TX Data | RX Data | |
PMA Width = 8, 10, 16, 20, 32 Double Width |
79 | Write Enable for TX Core FIFO in Elastic Mode29 | Data valid for RX Core FIFO in Elastic Mode29 | |
(40+D-1) + (80*n) | 40 + (80*n) | TX Data (Upper Data Bits) | RX Data (Upper Data Bits) | |
38 + (80*n) | TX PMA Interface Data Valid | RX PMA Interface Data Valid | ||
(D -1) + (80*n) | 0 + (80*n) | TX Data (Lower Data Bits) | RX Data (Lower Data Bits) |
MSB | LSB | TX Parallel Data | RX Parallel Data |
---|---|---|---|
77 | Alignment Marker | - | |
72 | 40 | TX Data (Upper Data Bits) | RX Data (Upper Data Bits) |
38 | TX PMA Interface Data Valid Bit | RX PMA Interface Data Valid Bit | |
37 | Alignment Marker | Alignment Marker | |
32 | 2 | TX Data (Lower Data Bits) | RX Data (Lower Data Bits) |
1 | 0 | Sync Head |
N (Number of Lanes) | 1 | 2 | … | 4 | TX Parallel Data |
---|---|---|---|---|---|
Bits | 79 | 159 | 319 | Write Enable for TX Core FIFO in Elastic Mode. |
|
38 | 118 | … | 278 | TX PMA Interface Data Valid | |
31:0 | 118:80 | … | 271:240 | TX Data (Lower Data Bits) | |
71:40 | 151:120 | … | 311:280 | TX Data (Upper Data Bits) |