KS8999
Micrel
Note that the signal MRXER is not provided on the MII interface for the KS8999 for PHY mode operation and MTXER is not
represented for MAC mode. Normally this would indicate a receive / transmit error coming from the physical layer /MAC device,
but is not appropriate for this configuration. If the connecting device has a MRXER pin, this should be tied low on the other device
for reverse or if it has a MTXER pin in the forward mode it should also be tied low on the other device.
The following explains the KS8999 in PHY mode and MAC mode of operation:
KS8999 PHY Mode
MTXC
External
MAC
Controller
MTXD[3:0]
MTXEN
KS8999
In PHY
mode
MTXER
Figure 3. Data Sent from External MAC Controller to KS8999 PHY Mode
MRXC
External
MAC
Controller
MRXD[3:0]
MRXEN
KS8999
In PHY
Mode
Figure 4. Data Sent from PHY Mode to External MAC Controller
KS8999 MAC Mode
MRXC
KS8999
In MAC
mode
MTXD[3:0]
External
PHY
MTXEN
MTXER
Figure 5. Data Sent from PHY Device to KS8999 MAC Mode
MTXC
KS8999
In MAC
Mode
MRXD[3:0]
External
PHY
MRXDV
Figure 6. Data Sent from KS8999 PHY Mode to External PHY Device
January 2005
25
KS8999