pef20320 Infineon Technologies Corporation, pef20320 Datasheet - Page 215

• Manufacturer Part Number: pef20320
• Description: Multichannel Network Interface Controller For Hdlc With 32 Channels
• Manufacturer: Infineon Technologies Corporation

The accumulated access time for a single MUNICH32 channel, depending on the actual
frame size, is then related to the serial transfer time on a PCM system:
(3 + size)
The following two diagrams illustrate the overall results for two different ranges and their
corresponding resolution. As you can see, for frame size greater than 32 bytes the time
needed for MUNICH32 memory accesses drops below 5%. That means in a simple
communication subsystem (e.g. Primary Access Board) the CPU performance is also
reduced by 5% only and it is therefore not necessary to use a complex multiport memory
approach to reach a significant overall performance gain.
Figure 109
Frame Size 1 to 512
User’s Manual
Transmit:
Memory Bus Occuppancy
125 s.
25
20
15
10
%
5
0
1
32
read descriptor
write current descriptor address
write interrupt
read data (size)
64
96 128 160 192 224 256 288 320 352 384 416 448 480 512
215
3
1
1
accesses size
Number of Data Bytes
1
1
1
1
2
:
Ch=32
Ch=30
Ch= 1
Application Notes
1
2
3
4
5
:
ITD04696
PEB 20320
01.2000