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2.13 Address Match Interrupt Usage
2.13.1 Overview of the address match interrupt usage
The address match interrupt is used for correcting a ROM or for a simplified debugging-purpose monitor.
When the external bus is used for 8 bits, the address match interrupt is not used to the external areas.
The following is an overview of the address match interrupt usage.
(1) Enabling/disabling the address match interrupt
The address match interrupt enable bit can be used to enable and disable an address match interrupt.
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It is affected neither by the processor interrupt priority level (IPL) nor the interrupt enable flag (I flag).
(2) Timing of the address match interrupt
An interrupt occurs immediately before executing the instruction in the address indicated by the ad-
dress match interrupt register. Set the first address of the instruction in the address match interrupt
register. Setting a half address of an instruction or an address of tabulated data does not generate an
address match interrupt.
The first instruction of an interrupt routine does not generate an address match interrupt either.
(3) Returning from an address match interrupt
The address put in the stack when an address match interrupt occurs depends on the instruction not
yet executed (the instruction the address match interrupt register indicates). The return address is not
put in the stack. For this reason, to return from an address match interrupt, either rewrite the content
of the stack and use the REIT instruction or use the POP instruction to restore the stack to the state as
it was before the interrupt occurred and return by use of a jump instruction.
<Instructions whose address is added to by 2 when an address match interrupt occurs>
• 16-bit operation code instructions
• 8-bit operation code instructions given below
<Instructions whose address is added to by 1 when an address match interrupt occurs>
• Instructions other than those listed above
Figure 2.13.1. Unexecuted instructions and corresponding stacked addresses
Figure 2.13.1 shows unexecuted instructions and corresponding the stacked addresses.
(4) How to determine an address match interrupt
Address match interrupts can be set at two different locations. However, both location will have the
same vector address. Therefore, it is necessary to determine which interrupt has occurred; address
match interrupt 0 or address match interrupt 1. Using the content of the stack, etc., determine which
interrupt has occurred according to the first part of the address match interrupt routine.
Rev.2.00 Oct 16, 2006
REJ09B0340-0200
ADD.B:S
#IMM8,dest
OR.B:S
#IMM8,dest
STNZ.B:S
#IMM8,dest
CMP.B:S
#IMM8,dest
JMPS
#IMM8
MOV.B:S
#IMM,dest (However, dest = A0/A1)
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SUB.B:S
#IMM8,dest
MOV.B:S
#IMM8,dest
STZX.B:S
#IMM81,#IMM82,dest
PUSHM
src
JSRS
#IMM8
2. Address Match Interrupt
AND.B:S
#IMM8,dest
STZ.B:S
#IMM8,dest
POPM
dest
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