
95
IOWR/IORD Instruction Specifications
Section 6-5
Interrupt Failure (Same for PC Interrupt Bit Interrupts and IOWR (#CC00) Interrupts)
PC Interrupt Subroutine Completed Flag Changes
Note
The time chart shown here indicates the flag operations which are different
from the PC flag operations.
6-5
IOWR/IORD Instruction Specifications
The IOWR/IORD instructions are available only with the C200HX/HG/HE and
CS1-series PCs. They cannot be used for ASCII Units on Slave Racks.
6-5-1
IOWR Instruction (SPECIAL I/O UNIT WRITE)
The IOWR instruction can be used with the ASCII Unit in the following four
ways.
Interrupt Enable Flag
PC Interrupt Number
Interrupt Fail
The Interrupt Fail Flag turns ON at the
next cycle after an interrupt is not
received from the PC even though the
PC Interrupt Bit has turned ON. It stays
ON for only one cycle, then turns OFF.
1., 2.
MOV or OUT instruction
PC Interrupt
Subroutine
Completed Flag
PC Interrupt
Fail Flag
CPU Unit
ASCII Unit
4. ON PC
GOSUB
3.
The PC Interrupt Fail Flag may turn ON
sooner for IOWR (#CC00) interrupts
because PC interrupt notification is
included in the instruction.
IOWR (#CC00)
Toggles at completion of
each PC interrupt
subroutine
Start
Finish
PC interrupt
subroutine
PC interrupt
subroutine
Start
Finish
PC Interrupt
Subroutine
Completed Flag
n + 5
bit 01
(OFF to ON or ON to OFF)
C: Control code
S: (First source word)
D: Destination Unit No., (No. of Transfer Words)
The parts inside parentheses change according
to the control code.
IOWR
C
S
D
Содержание C200H-ASC11
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