MDS105 Datasheet, PDF (15/35 Pages) Zarlink Semiconductor Inc – Unmanaged 5-Port 10/100 Mbps Ethernet Switch

MDS105
Data Sheet
11.3 DA – DA Register
• Access: parallel interface, Read Only
• Address: h36
Returns 8 bit value DA (hexadecimal) if the parallel port connection is good. Otherwise, returns some other
value indicating failure.
11.4 MBCR – Multicast Buffer Control Register
• Access: parallel interface and I²C, Read/Write
• Address: h00
Bit [7:0] MAX_CNT_LMT
Maximum number of multicast
frames allowed to be buffered
inside the device at any one time
(Default = 80)
11.5 FCBST – FCB Buffer Low Threshold
• Access: parallel interface and I²C, Read/Write
• Address: h01
Bits [5:0]
Bit 6
Bit 7
BUF_LOW_TH
Buffer Low Threshold – the
number of free buffers below
which flow control or WRED is
triggered
Use IP precedence subfield
(TOS[0:2]) for Transmission
Priority
Use IP precedence subfield
(TOS[0:2]) for Drop Level
Note that, for Bits 6 and 7, Default = 0 means to use
TOS[3:5].
11.6 LPBT – Low Drop Precedence Buffer Threshold
• Access: parallel interface and I²C, Read/Write
• Address: h02
(Default = 3F)
(Default = 0)
(Default = 0)
Bits [7:0] LOW_DROP_CNT Number of frame buffers
reserved for low-drop traffic
(Default 3F)
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