MDS213
Data Sheet
30
Zarlink Semiconductor Inc.
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.
Note: FE: Frame Engine, SE: Search Engine
Table 2 - Frame Buffer Memory Usage for Managed Mode
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
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.
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
FE
1
Transmission
Queue
4 bytes x 128K
to 4 bytes x 1K
52 (4 level
priority)
26 Kbytes to 208Kbytes
(at 4 level priority)
FE
1
CPU/HISC Mailing
List
32 Bytes to 64
Bytes
(Programmable)
128 to 1K
4K bytes to
32 Kbytes
(at 32 Bytes each)
CPU, HISC & SE
1
VLAN Table
8 bytes x 4K
1
32 Kbytes
HISC & SE
1
VLAN MAC Table
8 bytes to 32
bytes x 2K
1
16 Kbytes to 64 Kbytes
HISC & SE
1
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
FE
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)
FE
HISC Mailing List
32 Bytes to 64
Bytes
(Programmable)
128 to 1K
4K bytes to
32 Kbytes
(at 32 Bytes each)
HISC & SE