DEC VT220 Technical Manual page 210

ACR ADDRESS B7F4H(WR)
06 05 04 03
02 01
00
BAUD
COUNTER/TIMER
DELTA DELTA DELTA DELTA
SET
MODE AND SOURCE
IP3 IP2 IPl IPO
SEL
I I
INT INT INT
IN IT
IBAD7 H} .. 41--------------------~ ..... (BADO HI
BIT VALUES
BiT 7
0
1
BiT 4-€ 000
001
010
011
100
101
110
1"
BiT 3
0
1
BIT 2
0
1
BIT
1 0
1
BIT 0 0
1
Figure C-8
SELECT BAUD RATE SET 1
SELECT BAUD RA TE SET 2
COUNTER MODE - EXTERNAL (IP2) SOURCE
COUNTER MODE - TxCA AT 1 X CLOCK OF
CHANNEL A Tx
COUNTER MODE - T.CB AT lX CLOCK OF
CHANNEL B T,
COUNTER MODE - CRYSTAL OR EXTERNAL
CLOCK (CLKI DIVIDED BY 16
TIMER MODE - EXTERNAL (lP2) SOURCE
TIMER MODE - EXTERNAL (IP21 SOURCE
DIVIDED BY 16
TIMER MODE - CRYSTAL OR EXTERNAL (ClK!
SOURCE
TIMER MODE - CRYSTAL OR EXTERNAL (ClK)
SOURCE DIVIDED BY 16
NO INTERRUPT ON CHANGE OF STATE
SET ISR BIT 7 ON DETECT OF CHANGE OF
STATE AT IP3
NO INTERRUPT ON CHANGE OF STATE
SET ISR BIT 7 ON DETECT OF CHANGE OF
STATE AT IP2
NO INTERRUPT ON CHANGE OF STATE
SET ISR BIT 7 ON DETECT OF CHANGE OF
STATE AT IPl
NO INTERRUPT ON CHANGE OF STATE
SET ISR BIT 7 ON DETECT OF CHANGE OF
STATE AT IPO
2681 DUART: Auxiliary Control
Register (ACR)
C-7