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S3C2500B
31
30 29 28 27 26 25
A
R
R
T
T
u
x
x
x
R
t
N
R
R
x
o
O
E
E
S
E
C
V
V
t
N
R
o
C
p
[18] Tx single flat (TxSFLAG)
0 = Double flag mode (a closing & opening flags are used to separate frames)
1 = Single flag mode (only one flags are used to separate frames)
[19] Tx loop-back mode (TxLOOP)
0 = Normal operation.
1= The tramsmit data output is internally connected to the receiver data input for self testing.
[20] Rx echo mode (RxECHO)
0 = Disable Tx auto-echo mode.
1 = Enable Rx echo mode.
[21] Tx abort extension (TxABTEXT)
0 = At least eight consecutive 1's are transmitted.
1 = At least 16 consecutive 1's are transmitted.
[22] Tx abort (TxABT)
0 = Normal
1 = Enable (at least eight consecutive 1's are transmitted.)
[23] Tx preamble (TxPRMB)
0 = Transmit a mark idle is time fill bit pattern.
1 = Transmit the content of HPRMB
[24] Tx data terminology ready (TxDTR)
0 = nDTR goes high level.
1 = nDTR goes low level.
[25] Rx frame discontinue (TxDISCON)
0 = Normal
1 = Ignore the currently received frame
[26] Tx No CRC (TxNOCRC)
0 = Disable
1 = CRC is not appended by hardware.
[27] Rx No CRC (RxNOCR)
0 = Disable
1 = Receiver does not check CRC by hardware.
(CRC is treated as data in any case)
[28] Auto enable (AutoEN)
0 = Normal operation. Even if the nCTS or nDCD become high, the transmitter can send
tx data and the receiver can receive rx data.
1 = If the nDCD or nCTS become high, the transmitter can not send tx data and the
receiver can not receive rx data.
[29] Transparent Rx Stop (TRxStop)
0 = Normal
[30] Tx reverse (TxREV)
0 = Normal
[31] Rx reverse (RxREV)
0 = Normal operation
24
21
23 22
20 19
T
R
T
T
T
R
T
T
x
x
x
x
x
x
x
x
N
D
D
P
A
E
L
A
O
I
T
R
B
C
O
B
C
S
R
M
T
T
H
O
R
C
B
O
P
E
C
O
X
N
T
Figure 8-14. HDLC Control Register (HCON) (Continued)
18 17 16
15 14
13 12 11
T
T
D
D
D
R
R
x
x
R
R
T
x
x
S
F
x
x
x
W
4
F
L
M
S
S
A
W
L
A
A
T
T
D
A
G
D
S
S
G
E
K
K
C
1 = Stop receive operation.
1 = Send Tx data reversly.
1 = Receive Rx data reversly.
HDLC CONTROLLER
10 9
8 7 6
5
4
3
T
B
R
D
D
D
T
D
x
R
P
R
T
x
x
R
4
G
E
L
x
x
E
x
W
E
L
E
E
N
N
R
D
N
E
N
N
S
N
2
1
0
D
R
T
T
x
x
x
R
R
R
S
S
S
8-35
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