Control Data 3100 Reference Manual page 139

23 18 17 16 00
74
1...-
(Approximate execution time: 7.0
J.Lsec.
+
response time.)
23 21 20 18 17 16 00
ch 0
IINT~I
23 00
Reject Instruction
ch
=
1/0 channel designator, 0-3
INT ="1" for interrupt upon completion
Instruction Description: This instruction transfers a 12-bit byte into the lower 12 bits of A or
a 24-bit word into all of A from an external equipment. Transferring 12 or 24 bits depends
upon whether a 3106 or 3107 I/O channel is used. (A) is cleared prior to loading and, in the
case of a 12-bit input, the upper 12 bits remain cleared.
Comments: Bits 00-16 at P and P
+
1 should be loaded with zeros.
NOTE
Bits 18, 19, and 20 are all zeros when a 3106 data channel is used. If the operation
with A involves the use of a 3107, these bits take on the following significance:
Bit 20
=
always a "0".
Bit 19
=
If bit 18
=
"1", the state of bit 19 is of no consequence.
If bit 18 = "0", a "1" in bit 19 signifies backward operation.
A "0" in bit 19 signifies a forward operation.
1/0 OPERATION WITH A
INSTRUCTION SEQUENCE
LOAD
START
(P)-F
(FCN REG)
REQUEST
BLOCK
CONTROL
f
READ
(P
+
1)
CHANNEL
BUSY?
(P
+
1)-ZO
(P)-Z'
-..
Rev. B
/
WAIT FOR BLOCK CONTROL
THEN S BUS PRIORITY.
ACTIVATE READ/
STORE Zo (P+ 1)
WRITE ON I/O
IN ONE REGISTER
CHANNEL 0 - 3
(00- 03)
YES
STORE
z'
(P)
, IN ONE REGISTER
(10- 13)
OPERATION NO
1
RNI
~
WITH A?
FROM
P+3
~
7-82
REJECT
TO
P+2
RELEASE BLOCK
,. CONTROL AND
SCANNER
~