ZL50400 Datasheet, PDF (81/124 Pages) Zarlink Semiconductor Inc – Lightly Managed/Unmanaged 9-Port 10/100 M Ethernet Switch

ZL50400
12.3.6.2 UCC – Unicast Congestion Control
I²C Address h068, CPU Address: 510
Accessed by CPU and I²C (R/W)
Data Sheet
Bits [7:0]:
Number of frame count. Used for best effort dropping at B% when destination
port’s best effort queue reaches UCC threshold and shared pool is all in use.
Granularity is 16 granule (Default 0x6)
12.3.6.3 MCC – Multicast Congestion Control
I²C Address h069, CPU Address: 511
Accessed by CPU and I²C (R/W)
Bits [7:0]:
In multiples of 16 granules (granularity). Used for triggering MC flow control
when destination port’s multicast best effort queue reaches MCC threshold.
(Default 0x6)
12.3.6.4 MCCTH – Multicast Threshold Control
CPU Address: 512
Accessed by CPU (R/W)
Bits [7:0]: ^{Threshold on the multicast granule count. Exceeding the threshold consider as}
multicast resource low and the new multicast will be dropped at B% or flow con-
trol is triggered if enabled. (Default: 0x3)
12.3.6.5 RDRC0 – WRED Rate Control 0
I²C Address 090, CPU Address 513
Accessed by CPU and I²C (R/W)
Bits [3:0]:
Bits [7:4]:
Corresponds to the frame drop percentage Y% for WRED. Granularity
6.25%.
Corresponds to the frame drop percentage X% for WRED. Granularity
6.25%.
See Programming QoS Registers application note, ZLAN-42, for more information
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Zarlink Semiconductor Inc.