
Programmable Four-Channel Communications Controller
—
CD2481
Datasheet
95
Note:
If parity is used, parity is computed/checked on each character but the LRC of the parity bits is not
checked.
7.6.5
Receive State Tables
The tables on the following pages show the Bisync state transitions with in the Bisync receive
microcode character processing and the definition of the states.
Table 15. Bisync Receive State Transition
(Sheet 1 of 2)
(see
“
Key
”
on page 96
)
Character
Received
BGETHDR
0
BESCF
1
BESCL
2
BGETxT
3
BBCC
4
BBCC2
5
BWEOT
6
BXP
7
BDIS
8
SYN
0
hunt
7
3
5 CRC
CRC
2
6
7
CRC
8
DLE, RxITB = 0
1 i
hunt
7 CRC
1 CRC
5 CRC
CRC
b
6
2
8
DLE, RxITB = 1
2 i CRC
hunt
7 CRC
1 CRC
5 CRC
CRC
b
6
2
8
ENQ, SOHf = 1
hunt
hunt
hunt
hunt
Abort
0-RxITB
5 CRC
CRC
b
6
7
CRC
8
ENQ, SOHf = 0
STXf = 0
hunt
hunt
hunt
hunt
0-RxITB
5 CRC
CRC
b
6
7
CRC
8
ENQ, SOHf = 0
STXf = 1, no data
hunt
hunt
hunt
hunt
0-RxITB
‘
TTD
’
5 CRC
CRC
b
6
7
CRC
8
ENQ, SOHf = 0
STXf = 1, data
hunt
hunt
hunt
hunt
Abort
0-RxITB
5 CRC
CRC
b
6
7
CRC
8
EOT, SOHf = 1
hunt
hunt
7 CRC
3 CRC
5 CRC
CRC
b
6
7
CRC
8
EOT, SOHf = 0
STXf = 0
hunt
hunt
7 CRC
hunt
5 CRC
CRC
b
6
7
CRC
8
EOT, SOHf = 0
STXf = 1
hunt
hunt
7 CRC
3 CRC
5 CRC
CRC
b
6
7
CRC
8
STX
3 i
3
1-STXf
7
4
7 CRC
5
3 CRC
5 CRC
CRC
b
6
7
CRC
8
SOH
3 i
c
1-SOHf
hunt
7 CRC
3 CRC
5 CRC
CRC
b
6
7
CRC
8
ETX
RxITB = 1
4 CRC
0-RxITB
hunt
4 CRC
0-RxITB
4 CRC
0-RxITB
5 CRC
CRC
b
6
7
CRC
8
ETB
RxITB = 1
4 CRC
0-RxITB
hunt
4 CRC
0-RxITB
4 CRC
0-RxITB
5 CRC
CRC
b
6
7
CRC
8
ITB
6
hunt
4 CRC
1-RxITB
4 CRC
1-RxITB
5 CRC
CRC
b
6
7
CRC
8
ETX
RxITB = 0
6
hunt
4 CRC
0-RxITB
4 CRC
0-RxITB
5 CRC
CRC
b
6
7
CRC
8