E-110 Core Interface Signals
3-27
E110_TPAB
E-110 Transmit Abort
Input
When asserted, the E110_TPAB signal indicates that the
transmission was discontinued. E110_TPAB remains
asserted until the E-110 MAC receives a request to
transmit, which is indicated when the E-1110 asserts
E110_TPSF. When deasserted, E110_TPAB indicates
that the transmission was not aborted. The following
circumstances cause the transmission to be halted:
Excess deferrals, which occur when the media is busy
longer than twice the maximum frame length (greater
than 24,2881 bits when the HUGE_PKT_EN signal is
deasserted or greater than 524,2882 bits when
HUGE_PKT_EN is asserted)
Late collision
Multiple collisions (greater than 15)
Transmit underrun
Larger than normal packet, which is 1518 bytes (see
the HUGE_PKT_EN signal description)
E110_TRST_L
E-110 Transmit Reset
Input
Other modules in an ASIC can use the active-LOW
E110_TRST_L signal as a host reset synchronized to the
transmit clock (MII_TCLK). Because the MII_TCLK clock
can be slow with respect to a host reset pulse, or even
stopped, the E-1110 reset signal (E110_HRST_L) is
captured in the E-110 MAC transmit function. The
transmit function asserts E110_TRST_L asynchronously
to MII_TCLK when the E110_HRST_L signal occurs and
deasserts E110_TRST_L synchronously on the positive
transition of MII_TCLK. Modules can use E110_TRST_L
to initialize transmit logic.
1. 24,288 bits = 1518 bytes x 8 bits/byte x 2 (242.88
s for 100 Mbits/s operation or 2.4288
ms for 10 Mbits/s operation)
2. 524,288 bits = 32 Kbytes x 8 bits/byte x 2 (5242.88
s for 100 Mbits/s operation or 52.43
ms for 10 Mbits/s operation)