CD2231

Manufacturer Part NumberCD2231
DescriptionCD2231 Intelligent Two-channel Lan And Wan Communications Controller
ManufacturerIntel Corporation
CD2231 datasheet
 


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
Page 91
92
Page 92
93
Page 93
94
Page 94
95
Page 95
96
Page 96
97
Page 97
98
Page 98
99
Page 99
100
Page 100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
Page 96/178

Download datasheet (3Mb)Embed
PrevNext
CD2231 — Intelligent Two-Channel LAN and WAN Communications Controller
8.2.4.2
HDLC Mode
Register Name: COR3
Register Description: Channel Option Register 3
Default Value: x’00
Access: Byte Read/Write
Bit 7
Bit 6
Bit 5
sndpad
Alt1
FCSPre
In Synchronous mode, COR3 is used to specify the learning pattern (pad character) sent by the
CD2231 to synchronize the DPLL at the remote end. The pad character (00h or AAh) sent depends
on the kind of encoding used.
Bit 7
Sends pad character(s)
1 = CD2231 sends pad character(s) before sending flag when coming out of the Idle-
in Mark mode.
0 = CD2231 does not send any pad character.
Bit 6
alt1 – send sync pattern
1 = AAh (Manchester/NRZ encoding) is sent as pad character.
0 = 00h (NRZI encoding) is sent as pad character.
Bit 5
FCS preset
0 = FCS is preset to all ‘1’s (CRC V.41).
1 = FCS is preset to all ‘0’s (CRC-16).
Bit 4
FCS mode
1 = Disables FCS generation and checking. The CD2231 treats the entire frame as
data.
0 = Normal FCS mode. The CD2231 generates and appends CRC on transmit and
validates CRC on receive using the CRC polynomial selected through the CRC Poly-
nomial Select register.
Bit 3
Idle mode
0 = Idle-in Flag mode
1 = Idle-in Mark mode
Bits 2:0
Character Count – specifies the number of synchronous characters sent.
96
Bit 4
Bit 3
FCS
idle
npad2
npad1
npad0
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
101–111 are reserved.
Intel Hex Address: x’15
Motorola Hex Address: x’16
Bit 2
Bit 1
Bit 0
npad2
npad1
npad0
Reserved
1 pad character sent
2 pad characters sent
3 pad characters sent
4 pad characters sent
Datasheet