U-Boot驱动AR8031的问题

marianna_2010

飞凌工程师，你好！

我使用OK335xD的核心板，自己绘制了一块底板，使用的PHY芯片是AR8031，网络变压器型号是HR911130C。现在遇到的问题是：

1. 使用AM335x扫描MDIO设备时，打印的MDIO寄存器值为：
maria: ----> 40070106
maria: ----> 410004ff
maria: ----> 10
maria: ----> 0
maria: ----> 0
maria: ----> 0
maria: ----> 1
maria: ----> 0
maria: ----> 0
maria: ----> 0
maria: ----> 3e0ffff
maria: ----> 0
maria: ----> 0
maria: ----> 0

这说明它扫描到的PHY地址是4，而不是0。尝试个二十次，可能突然就出现一次正确的PHY地址为0的情况。这是为什么呢？

2.使用PHY地址为4的时候，获取的AR8031寄存器的值为：
AR8031: final temp = 0x3100
AR8031: final temp = 0x7949
AR8031: final temp = 0x4d
AR8031: final temp = 0xd074
AR8031: final temp = 0x11e1
AR8031: final temp = 0x0
AR8031: final temp = 0x4
AR8031: final temp = 0x2001
AR8031: final temp = 0x0
AR8031: final temp = 0x200
AR8031: final temp = 0x0
AR8031: final temp = 0x0
AR8031: final temp = 0x0
AR8031: final temp = 0x0
AR8031: final temp = 0x0
AR8031: final temp = 0xa000
AR8031: final temp = 0x862
AR8031: final temp = 0x10
AR8031: final temp = 0x0
AR8031: final temp = 0x0
AR8031: final temp = 0x82c
AR8031: final temp = 0x0
AR8031: final temp = 0x4e8
AR8031: final temp = 0x0
AR8031: final temp = 0x3200
AR8031: final temp = 0x3000
AR8031: final temp = 0x0
AR8031: final temp = 0x600
AR8031: final temp = 0x0
AR8031: final temp = 0x0
AR8031: final temp = 0x82ee
AR8031: final temp = 0x8100

而把SD卡从底板上拔下来，插到开发板上，打印出来的信息为：
AR8031: final temp = 0x3100
AR8031: final temp = 0x7949
AR8031: final temp = 0x4d
AR8031: final temp = 0xd074
AR8031: final temp = 0x11e1
AR8031: final temp = 0x0
AR8031: final temp = 0x4
AR8031: final temp = 0x2001
AR8031: final temp = 0x0
AR8031: final temp = 0x200
AR8031: final temp = 0x0
AR8031: final temp = 0x0
AR8031: final temp = 0x0
AR8031: final temp = 0x0
AR8031: final temp = 0x0
AR8031: final temp = 0xa000
AR8031: final temp = 0x862
AR8031: final temp = 0x10
AR8031: final temp = 0x0
AR8031: final temp = 0x0
AR8031: final temp = 0x82c
AR8031: final temp = 0x0
AR8031: final temp = 0x4e8
AR8031: final temp = 0x0
AR8031: final temp = 0x3200
AR8031: final temp = 0x3000
AR8031: final temp = 0x0
AR8031: final temp = 0x600
AR8031: final temp = 0x0
AR8031: final temp = 0x0
AR8031: final temp = 0x82ee
AR8031: final temp = 0x8100

它们有些不一样，能不能告诉我问题出在哪里？

另外，我使用的25MHz的晶振电容是18pF，也试过27pF的，现象都一样。开发板上的电容是22pF的，是这个导致的吗？

marianna_2010

暂时推测是布线的问题。