A newer version of this document is available. Customers should click here to go to the newest version.
Visible to Intel only — GUID: puo1681940777221
Ixiasoft
Visible to Intel only — GUID: puo1681940777221
Ixiasoft
3.7. Custom Cadence Generation Ports and Logic
When using system PLL clocking mode, you must enable the Custom cadence generation (CCG) ports and logic parameter for the use cases that the Custom Cadence Generation Ports and Logic Use Cases table below describes. Enabling CCG logic ensures that the TX PMA interface FIFO does not overflow due to the over clocking of the datapath when using system PLL clocking mode.
Configuration | Datapath Clocking mode | System PLL Frequency | Enable Custom Cadence Generation (CCG) Ports and Logic |
---|---|---|---|
PMA Direct | PMA | N/A | No |
PMA Direct | System PLL | Equal to PMA parallel clock frequency. No PPM between PMA parallel clock frequency and system PLL frequency. That is, the same reference clock source for PMA and system PLL.30 | No |
PMA Direct | System PLL | Greater than the PMA parallel clock frequency. | Yes |
FEC Direct | System PLL | Equal to the PMA Parallel clock frequency. No PPM between PMA parallel clock frequency and system PLL frequency. That is, the same reference clock source for PMA and system PLL. | No |
FEC Direct | System PLL | Equal to the PMA Parallel clock frequency. PPM between PMA parallel clock frequency and system PLL frequency. That is, different reference clock for PMA and system PLL. | Yes |
FEC Direct | System PLL | Greater than the PMA parallel clock frequency. | Yes |
Configuration | Enable TX Double Width Transfer | Recommended Connections |
---|---|---|
PMA Direct | Yes |
|
PMA Direct | No |
|
FEC Direct | Yes |
|