MDS213 Datasheet, PDF (30/120 Pages) Zarlink Semiconductor Inc – 12-Port 10/100Mbps + 1Gbps Ethernet Switch

MDS213
Data Sheet
5.2 Frame Buffer memory usage
The MDS213 supports two switching modes: managed and unmanaged. The following tables describe Frame
Buffer Memory usage for managed and unmanaged modes of operation, respectively.
Description
Unit Size
Unit Count
Total Size
Frame Data Buffer
(FDB)
1.5 Kbytes
256 to 1K
384 K bytes to 1.5M bytes
Transmission
Queue
4 bytes x 128K
to 4 bytes x 1K
52 (4 level
priority)
26 Kbytes to 208Kbytes
(at 4 level priority)
CPU/HISC Mailing
List
32 Bytes to 64
Bytes
(Programmable)
128 to 1K
4K bytes to
32 Kbytes
(at 32 Bytes each)
VLAN Table
8 bytes x 4K
1
32 Kbytes
VLAN MAC Table 8 bytes to 32
1
bytes x 2K
16 Kbytes to 64 Kbytes
Note: FE: Frame Engine, SE: Search Engine
Table 2 - Frame Buffer Memory Usage for Managed Mode
Reference by
FE¹
FE¹
CPU, HISC & SE¹
HISC & SE¹
HISC & SE¹
Description
Unit Size
Unit Count
Total Size
Reference by
Frame Data Buffer
(FDB)
1.5 Kbytes
256 to 1K 384 K bytes to 1.5M bytes
Transmission
Queue
4 bytes x 128 to
4 bytes x 1K
52 (4 level
priority)
13 (1 level
priority)
26 Kbytes to 208 Kbytes
(at 4 level priority)
HISC Mailing List
32 Bytes to 64
Bytes
(Programmable)
128 to 1K
4K bytes to
32 Kbytes
(at 32 Bytes each)
Note: FE: Frame Engine, SE: Search Engine
In unmanaged mode, the system does not support VLAN features. Thus, VLAN related tables are not required.
Table 3 - Frame Buffer Memory Usage For Unmanaged Mode
FE
FE
HISC & SE
5.2.1 Memory Allocation of a Managed System
In a managed system, the Frame Buffer Memory is partitioned into five segments: Frame Data Buffers (FDBs),
Transmission Queues, Mailing Lists, VLAN, and MCT VLAN Association Tables.
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