108
STP2002QFP
Sun Microelectronics
Fast Ethernet, Parallel Port, SCSI (FEPS) - STP2002QFP
7.5.23 ERX RxFIFO Shadow Write Pointer
This nine-bit register points to the first word of the packet that is either cur-
rently being loaded or is about to be loaded into the FIFO. The register is
loaded with the contents of the write pointer after the packet transfer from the
RX_MAC to the FIFO has been completed. This register is used to perform
an early receive abort.
7.5.24 ERX RxFIFO Read Pointer
This nine-bit loadable counter points to the next location in the RxFIFO that
will be read from to retrieve packet data that is transferred to the host memo-
ry. The counter increments by 1 or 2 after a word (or double word) was read
from the FIFO. This counter generates the read address for the RxFIFO mem-
ory core.
Table 130: ERX RxFIFO Write Pointer Register Definition
Field Bits Description Type
8:0 Counter, points to the next location in RxFIFO
that will receive data from RX_MAC
R/W
Table 131: ERX RxFIFO Shadow Write Pointer Register Address
Register Physical Address Access Size
ERX RxFIFO shadow write pointer register 0x8C0_4010 4 bytes
Table 132: ERX RxFIFO Shadow Write Pointer Register Definition
Field Bits Description Type
8:0 Points to the first word of the packet that is either
currently being loaded or to be loaded into the
FIFO
R/W
Table 133: ERX RxFIFO Read Pointer Register Address
Register Physical Address Access Size
ERX RxFIFO read pointer register 0x8C0_4014 4 bytes