DEC VT220 - 2681 DUART: Status Register (SR) (Channel A and B)

SRA ADDRESS
SRB ADDRESS
B7F1 H (RD)
B7F9H IRD)
07
06 05
04
03
02 01
00
RECEIVE
FRAME PARITY
OVER
T,
T,
Rx
BREAK ERROR
ERROR
RUN
EMT
ROY
HULL
ROY
ERROR
IBAD7 HI ..... t-------------------- ....... (BADO Hi
BIT VALUES
BIT 7
0
1
BiT 6 0
1
BIT 5
0
1
BIT 4
0
1
BiT 3
0
1
BIT 2
0
1
B'T 1
0
1
BIT 0
0
1
Figure C-3
NO BREAK DETECTED
RECEIVE BREAK DETECTED
NO ERROR
FRAMING ERROR
NO ERROR
PARITY ERROR
NO ERROR
OVERRUN ERROR
Tx NOT EMPTY
1. HOLDiNG AND SHIFT REGISTERS EMPTY
T, HOLDING REGISTER FULL
Tx HOLDING REGISTER EMPTY
R, FIFO NOT FULL
Rx FIFO FULL
NO
Rx DATA WAiTING
Rx DATA IN FIFO
... 4·067 .....
2681 DUART: Status Register
(SR) (Channel A and B)
C-3