
92
Data Exchange Time Charts
Section 6-4
Interrupt by PC Interrupt Bit
Note
Areas within dotted lines denote retry processing when PC interrupt has failed
due to conditions such as a PC OFF (stop interrupt) condition in the ASCII
Unit. If an interrupt is not accepted due to PC OFF condition when attempting
to execute the interrupt by turning ON the PC Interrupt Bit (word n bit 04), the
Interrupt Fail Flag (word n + 5 bit 09) will be set to ON (1) for one scan in the
next cycle.
Execution condition
ON for 1 cycle
n + 5 bit
09
PC Interrupt
Fail Flag
Interrupt Subroutine
Completed Flag
n bit 04 PC
Interrupt Bit
Detect toggled
flag
Interrupt
subroutine
completion
processing
PC interrupt enabled
condition
Interrupt subroutine
n + 5
bit 01
1.
2.
3.
4.
5.
6.
7.
CPU Unit
ASCII Unit
MOV
a
n+2
A
B
DIFU A
DIFD B
1000
100
110
ON PC a
GOSUB 1000
PC
RETURN
a
ON
PC Interrupt Bit
PC Interrupt Number
PC Interrupt Subroutine
Completed Flag toggles
(OFF to ON or ON to OFF)
1.
2.
n
n + 2
n + 5
I/O refresh
3.
4.
5.
6.
4
7
0
1
a
Содержание C200H-ASC11
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