PEB20534H-10 SIEMENS [Siemens Semiconductor Group], PEB20534H-10 Datasheet - Page 189

• Manufacturer Part Number: PEB20534H-10
• Description: DMA Supported Serial Communication Controller with 4 Channels DSCC4
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

This mechanism is applied to asynchronous HDLC PPP mode as well as to octet
synchronous HDLC PPP mode.
Figure 70
Semiconductor Group
data in
transmit
FIFO:
HDLC
framing:
PPP
mapping:
serial
line
received
character:
PPP
unmapping:
data in
receive
FIFO:
Note: CRC generation/checking is assumed to be disabled in this example; according the PPP
mapping/unmapping, CRC characters are treated as ’data’ characters being mapped/unmapped if
necessary .
ACCM: Async Control Character Map Register
31
1F
UDAC: User Defined Async Control Character Map Register
31
0
1E
0
PPP Mapping/Unmapping Example
7E
7E
7Eh
H
H
...
...
7E
7E
H
H
24 23
24 23
13
13
7D
7D
H
H
H
H
33
33
13
13
15
H
H
H
H
0
14
20
20
7D
7D
0
7Eh
19
13
H
H
1
H
H
12
00
00
20
20
0
11
H
H
H
H
0
189
16 15
16 15
01
01
01
H
H
H
01
01
01
H
H
H
02
02
02
7Eh
H
H
H
...
...
Detailed Protocol Description
02
02
02
H
H
H
7E
7E
8 7
8 7
H
H
7E
7E
H
H
20h
Data Sheet 09.98
PEB 20534
00
0
0
0