LAN9313 Datasheet, PDF (367/398 Pages) SMSC Corporation – Three Port 10/100 Managed Ethernet Switch with MII

Three Port 10/100 Managed Ethernet Switch with MII
Datasheet
13.3.4.11 Buffer Manager Random Discard Table Write Data Register (BM_RNDM_DSCRD_TBL_WDATA)
Register #:
1C0Ah
Size:
32 bits
This register is used to write the Random Discard Weight table.
Note: The Random Discard Weight table is not initialized upon reset or power-up. If a random discard
is enabled, the full table should be initialized by the host.
BITS
DESCRIPTION
31:10 RESERVED
9:0 Drop Probability
These bits specify the discard probability of a packet that has been colored
Yellow by the ingress metering. The probability is given in 1/1024’s. For
example, a setting of 1 is one in 1024, or approximately 0.1%. A setting of
all ones (1023) is 1023 in 1024, or approximately 99.9%.
There are a total of 16 probability entries. Each entry corresponds to a range
of the number of buffers used by the ingress port, as specified in Section
13.3.4.10, "Buffer Manager Random Discard Table Command Register
(BM_RNDM_DSCRD_TBL_CMD)".
TYPE
RO
R/W
DEFAULT
-
000h
SMSC LAN9313/LAN9313i
367
DATASHEET
Revision 1.2 (04-08-08)