DEC VT220 Technical Manual page 208

CRA ADDRESS
CRB ADDRESS
B7F2H(WR)
B7FAH(WR)
07 06 05
04
03
02 01 00
I
I
NOT
MISC COMMANDS
DISABLE
ENABLE
DISABLE ENABLE
USED
T. T. R.
R.
IJ
(BAD7 HI ....
I-------------------••
(BADO HI
BIT VALUES
BIT 7
BIT 4-6 000
001
010
011
100
101
110
111
BIT 3
0
1
BIT 2
0
1
BtT 1 0
1
BIT 0 0
1
Figure C-5
ALWAYS 0
NOT USED
RESET MODE REGISTER (MRI POINTER
RESET R.
RESET
Tx
RESET ERROR STATUS
RESET CHANNEL BREAK CHANGE INTERRUPT
START BREAK
STOP BREAK
NO COMMAND
TERMINATE Tx AND RESET TxRDY AND TxEMT
STATUS BITS
DISABLE Tx
ENABLE Tx
NO COMMAND
TERMINATE R. IMMEDIATELY
DISABLE Rx
ENABLE Rx
2681 DUART: Command Register
(CR) (Channel A and B)
RDRA ADDRESS
RDRB ADDRESS
TDRA ADDRESS
TDRB ADDRESS
B7F3H(RD)
B7FBH(RD)
B7F3H(WR)
B7FBH(WR)
07
06 05 04 03 02 01 00
IBAD7 HI..... . . - - - - - - - - - - - - - - - - - -•• (BADO HI
BIT VALUES
BIT 0-7
Figure C-6
DATA RECEIVED FROM HOST (RDRAI
DATA RECEIVED FROM PRINTER IRDRBI
DATA TO TRANSMIT TO HOST {TORA!
DATA TO TRANSMIT TO PRINTER (TORB)
2681 DUART: Receive/Transmit
Data Registers (RDR/TDR)
(Channel A and B)
C-5