[dm9000a ping 不通，知道的麻烦说一下，在这堵住好几天了]

x86架构下，vxWorks系统，dm9000a作为添加的第二块网卡，调用muxShow和ifShow后的信息如下：
> muxShow
Current mode: NORMAL
Device: fei Unit: 0
Description: Intel 82557 Ethernet Enhanced Network Driver
Protocol: IP 4.4 ARP    Type: 2054    Recv 0x390500    Shutdown 0x390930
Protocol: IP 4.4 TCP/IP    Type: 2048    Recv 0x390500    Shutdown 0x3907f0
Device: dm Unit: 0
Description: DM9000A Ethernet Enhanced Network Driver
Protocol: IP 4.4 ARP    Type: 2054    Recv 0x390500    Shutdown 0x390930
Protocol: IP 4.4 TCP/IP    Type: 2048    Recv 0x390500    Shutdown 0x3907f0
value = 0 = 0x0
-> ifShow"dm"
dm (unit number 0):
    Flags: (0x8963) UP BROADCAST RUNNING ARP PROMISCUOUS MULTICAST
    Type: ETHERNET_CSMACD
    Internet address: 192.168.22.7
    Broadcast address:   192.168.22.255
    Netmask 0xffffff00 Subnetmask 0xffffff00
    Ethernet address is 00:01:02:03:04:05
    Metric is 0
    Maximum Transfer Unit size is 1500
    0 packets received; 1 packets sent
    0 multicast packets received
    0 multicast packets sent
    0 input errors; 0 output errors
    0 collisions; 0 dropped
value = 0 = 0x0
然后ping 包，发现先进入link status changed的中断，然后进入收中断，包的状态信息显示：

0xf6d1478 (tNetTask): crc error  !
0xf6d1478 (tNetTask): Physical Layer error !
（我是用logMsg输出的打印信息）
各位大大，知道是什么原因么？

中断 INT脚上面始终为低电平，不知道为什么，知道的说一声啊！