3-26
Signals
asserts E110_TPRT until the MAC receives a fresh
request to transmit, which is indicated when the
E110_TPSF signal is asserted.
E110_TPUD
E-110 Transmit Packet Data Used
Input
The E-110 MAC asserts the E110_TPUD signal to
indicate that the preamble has been transmitted. Every
two clocks thereafter, the E-1110 must place the
E110_TPD[7:0] signals on the bus for the E-110 MAC.
The MAC keeps E110_TPUD asserted until the MAC
accepts all the data bytes in the transmit packet from the
E-1110.
E110_TPSF
E-110 Transmit Packet Start of Frame
Output
The E-1110 asserts the E110_TPSF signal to request the
E-110 core to transmit a new packet. The E-1110 keeps
the E110_TPSF signal asserted for one transmit clock
period after the E-110 core asserts the E110_TPUD
signal. The E110_TPSF signal is synchronous to
MII_TCLK.
E110_TPUR
E-110 Transmit Data Underrun Error
Output
When the E-1110 MAC asserts the E110_TPUR signal,
the E-110 MAC discontinues transmission. If the E-1110
is unable to supply transmit packet data bytes in a timely
manner to the E-110 core (an underrun condition), the
E-1110 asserts TPUR.
The E-1110 asserts E110_TPUR for at least two
MII_TCLK clock cycles. The MAC asserts E110_TPAB
and MII_TXER in the very next clock cycle and deasserts
MII_TXEN one cycle after MII_TPAB and MII_TXER are
asserted. Deassertion of MII_TXEN indicates the end of
transmission.
E110_TPDN
E-110 Transmit Done
Input
When asserted, the E110_TPDN signal indicates
successful completion of the packet transmit process.
The MAC keeps E110_TPDN asserted until the MAC
receives a fresh request to transmit, which is indicated
when the E-1110 asserts the E110_TPSF signal.