Table 5-39 Switching Characteristics Over Recommended Operating Conditions for EMAC RGMII Transmit - RGMII_TXD[3:0], and RGMII_TXCTL - RGMII Mode (1)
NO. |
PARAMETER |
MIN |
MAX |
UNIT |
RGMII5 |
td(TXD-TXC) |
Delay time, TXD to TXC |
-0.35 |
0.65 |
ns |
RGMII6 |
td(TXCTL-TXC) |
Delay time, TXCTL to TXC |
-0.35 |
0.65 |
ns |
RGMII7 |
tt(TXD) |
Transition time, TXD |
|
0.75 |
ns |
RGMII8 |
tt(TXCTL) |
Transition time, TXCTL |
|
0.75 |
ns |
- PCB traces for RGMII_TXD[3:0] and RGMII_TXCTL should insert an additional 150ps of delay relative to the PCB trace delay of RGMII_TXC. This provides the expected output timing as defined by the RGMII specification for a transmitter not operating in RGMII-ID timing mode. Timing analysis should be performed on this interface using actual timing requirements/characteristics of the attached RGMII PHY. In some cases, additional PCB delays may be required to provide proper timing margins.