Thank to answer this question。
There are some problem about the chip P2020，I using 2 ETH PHY in this project，which using in TSEC1 and TSEC3。TSEC1 is no problem and it can ping the computer。But the other one，TSEC3 ，which is unable to ping computer。TSEC1 and TSEC3 using the same PHY and the same schematic。And TSEC3's PHY can recognize the Internet is 100M or 1000M，but can not Ping computer。Thanks！
Please provide additional information:
1) complete schematics of the Ethernet connections as PDF - not pictures
2) value of the GUTS_PORDEVSR
3) raw memory dump of the eTSEC3 CCSR registers
Please refer to the PORDEVSR value 0x1A000000 to see that:
ECW=0 - eTSEC1 and eTSEC2 Ethernet interfaces operate in reduced pin mode
ECP1=10 - RGMII
ECP2=00 - Reserved
ECP3=00 - Reserved
It is required to check strapping of cfg_tsec3_prtcl (UART_RTS0_B).
But UART_RTS0_B is using internal pullup and didn't connected to another pin，this pin will not be pulldown by another signal or resister。When the H_Rest reset,this pin is High level.
> I found that using Jtag to read the register is right，
> but when the VxWorks is working or rebooting，and then read the register is wrong
What is the whole sequence?
1) I.e. when JTAG read is performed?
2) Is any reset applied after that before VxWorks starts?
3) Is the same method used to read the register when VxWorks is running?
As you said,the register need used unique Code to read after VxWorks is running。
Now we get the value by VxWorks is equal to the Jtag's value.
But also can not ping the computer.
Thank you very very very very much.
The second PHY is no Problem。Because of the register was wrong，and I change the register and then soft reset the PHY，after that MAC can receive the data and can ping the computer。
The register as this.Chang this register to 0xce2 is fine。