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Section
Interrupt Control Instructions
502
Note
This instruction is not supported by SRM1(-V2) PCs.
Limitations
DM 6144 to DM 6655 cannot be used for C2 when C1=002.
When the execution condition is OFF, INT(89) is not executed. When the execu-
tion condition is ON, INT(89) is used to control interrupts and performs one of the
seven functions shown in the following table depending on the value of C1.
C1
INT(89) function
000
Mask/unmask interrupt inputs
001
Clear interrupt inputs
002
Read current mask status of interrupt inputs
003
Restart decrementing counter and unmask interrupt
004*
Restart incrementing counter and unmask interrupt
100
Mask all interrupts
200
Unmask all interrupts
Note
*This setting can be used in CPM2A/CPM2C PCs only.
This function is used to mask and unmask interrupt inputs 00003 to 00006.
Masked inputs are recorded, but ignored. When an input is masked, the interrupt
program for it will be run as soon as the bit is unmasked (unless it is cleared be-
forehand by executing INT(89) with C1=001).
Set the corresponding bit in C2 to 0 or 1 to unmask or mask an interrupt input.
Bits 00 to 03 correspond to 00003 to 00006. Bits 04 to 15 should be set to 0.
Interrupt input 00003 (0: unmask, 1: mask)
Interrupt input 00004 (0: unmask, 1: mask)
Interrupt input 00005 (0: unmask, 1: mask)
Interrupt input 00006 (0: unmask, 1: mask)
Word C2 bits: 3 2 1 0
All of the interrupt inputs are masked at the start of PC operation, so the inputs
must be unmasked in order to be used.
This function is used to clear interrupt inputs 00003 to 00006. Since interrupt in-
puts are recorded, masked interrupts will be serviced as soon as the mask is re-
moved unless they are cleared first.
Set the corresponding bit in C2 to 1 to clear an I/O interrupt input. Bits 00 to 03
correspond to 00003 to 00006. Bits 04 to 15 should be set to 0.
Word C2 bits: 3 2 1 0
Interrupt input 00003 (0: Do not clear, 1: clear)
Interrupt input 00004 (0: Do not clear, 1: clear)
Interrupt input 00005 (0: Do not clear, 1: clear)
Interrupt input 00006 (0: Do not clear, 1: clear)
This function reads the current mask status for interrupt inputs 00003 to 00006
and writes that information to word C2. The corresponding bit will be ON if the
input is masked. (Bits 00 to 03 correspond to 00003 to 00006.)
Word C2 bits: 3 2 1 0
Interrupt input 00003 (0: not masked, 1: masked)
Interrupt input 00004 (0: not masked, 1: masked)
Interrupt input 00005 (0: not masked, 1: masked)
Interrupt input 00006 (0: not masked, 1: masked)
These functions are used to restart interrupt inputs (counter mode) by refreshing
the counter SV (in SR 240 to SR 243) and unmasking the interrupt input (00003
to 00006).
Description
Mask/Unmask Interrupt
Inputs (C1=000)
Clear Interrupt Inputs
(C1=001)
Read Current Mask Status
(C1=002)
Restart Counter and
Unmask Interrupt
(C1=003 or C1=004)