lan91c100 Standard Microsystems Corp., lan91c100 Datasheet - Page 38

• Manufacturer Part Number: lan91c100
• Description: Feast ? Ast Ethernet Controller
• Manufacturer: Standard Microsystems Corp.

I/O SPACE - BANK2
PACKET NUMBER AT TX AREA - The value
written into this register determines which
packet number is accessible through the TX
area. Some MMU commands use the number
This register is updated upon an ALLOCATE MEMORY MMU command.
FAILED A zero indicates a successful allocation
completion. If the allocation fails the bit is set
and only cleared when the pending allocation is
satisfied.
MMU command.
ALLOC_INT in the Interrupt Status Register
should be used because it is synchronized to the
read operation. Sequence:
FAILED
1) Allocate Command
2) Poll ALLOC_INT bit until set
3) Read Allocation Result Register
OFFSET
OFFSET
0
1
2
3
Defaults high upon reset and reset
0
0
For polling purposes, the
ALLOCATION RESULT REGISTER
PACKET NUMBER REGISTER
0
0
NAME
NAME
0
0
ALLOCATED PACKET NUMBER
PACKET NUMBER AT TX AREA
38
stored in this register as the packet number
parameter. This register is cleared by a RESET
or a RESET MMU Command.
ALLOCATED
number associated with the last memory
allocation request. The value is only valid if the
FAILED bit is clear.
Note:
versions, the value read from the ARR after an
allocation request is intended to be written into
the PNR as is, without masking higher bits
(provided FAILED = 0).
0
0
For software compatibility with future
READ/WRITE
READ ONLY
0
0
PACKET
TYPE
TYPE
NUMBER
0
0
SYMBOL
SYMBOL
PNR
ARR
0
0
Packet