103
STP2002QFP
Fast Ethernet, Parallel Port, SCSI (FEPS) - STP2002QFP
Sun Microsystems,
rewind the read pointer for frame retransmission due to a collision on the net-
work.
7.5.17 ETX State Machine Register
This 23-bit register provides the current state for all the state machines in
ETX.
7.5.18 ETX TxFIFO
For diagnostic purposes a PIO path has been provided into the TxFIFO. When
using PIOs, the configuration of the TxFIFO will be 512×33 bits. In order to
be able to access all the bits in the memory core, the address space of the
TxFIFO has been doubled and split into two apertures as follows:
Table 118: ETX TxFIFO Shadow Read Pointer Address
Register Physical Address Access Size
TxFIFO shadow read pointer register 0x8C0_2020 4 bytes
Table 119: ETX TxFIFO Shadow Read Pointer Definition
Field Bits Description Type
TxFIFO shadow read pointer 8:0 Points to first byte of the packet cur-
rently being unloaded or is about to
be unloaded from TxFIFO
R/W
Table 120: ETX State Machine Register Address
Register Physical Address Access Size
State machine register 0x8C0_2028 4 bytes
Table 121: ETX State Machine Register Definition
Field Bits Description Type
4:0 Checksum state machine state R
11:5 Chaining state machine state R
16:12 Unload control state machine state R
22:17 Load control state machine state R