E-110 Core Interface Signals
3-41
MII_TXEN
MII Transmit Enable
Input
The MII_TXEN signal indicates that the E-110 MAC is
presenting MII_TXD[3:0] nibbles to the E-1110 for
transmission. The MAC asserts MII_TXEN synchronously
with the rst nibble of the preamble. MII_TXEN remains
asserted while all nibbles to be transmitted are presented
to the MII. The MAC deasserts MII_TXEN prior to the rst
MII_TCLK following the nal nibble of a frame. MII_TXEN
is synchronous to the rising edge of MII_TCLK, and the
E-1110 samples MII_TXEN synchronously.
MII_TXER
MII Transmit Coding Error
Input
The E-110 MAC function asserts the MII_TXER signal
synchronously on the rising edge of MII_TCLK, and the
E-1110 samples MII_TXER synchronously. When the
MAC asserts MII_TXER for one MII_TCLK clock period
while MII_TXEN is also asserted, MII_TXER causes the
E-1110 to transmit one or more symbols that are not part
of the valid data or delimiter set somewhere in the frame
being transmitted to indicate that there has been a
transmit coding error. If the MAC asserts the MII_TXER
signal when the E-1110 is operating at 10 Mbits/s or
when MII_TXEN is deasserted, the E-1110 must not
allow the transmission of data to be affected.
MII_TXD[3:0] MII Transmit Data
Input
The MII_TXD[3:0] signals are synchronous to the rising
edge of MII_TCLK.
MII_MTXD[3:0] consists of four data signals that are
synchronous to MII_TCLK. For each MII_TCLK period in
which MII_TXEN is asserted, the E-1110 accepts the
MII_TXD[3:0] signals for transmission. MII_TXD[0] is the
least signicant bit. When MII_TXEN is deasserted, the
MII_TXD[3:0] signals have no effect on the E-1110.