On Wed, Dec 25, 2024 at 06:04:44PM +0800, Yijie Yang wrote: > The Ethernet MAC requires precise sampling times at Rx, but signals on the > Rx side after transmission on the board may vary due to different hardware > layouts. The RGMII_CONFIG2_RX_PROG_SWAP can be used to switch the sampling > occasion between the rising edge and falling edge of the clock to meet the > sampling requirements. The RGMII specification says that RD[3:0] pins are sampled on the rising edge for bits 3:0 and falling edge for bits 7:4. Given this is part of the standard, why would you want to do anything else? Is this maybe another symptom of having the RGMII delays messed up? Anyway, i don't see a need for this property, unless you are working with a PHY which breaks the RGMII standard, and has its clock reversed? Andrew