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1-49
4507 Group
HARDWARE
Rev.2.01
Feb 04, 2005
REJ09B0195-0201
Note [2] on bit 3 of register I1
When the bit 3 of register I1 is cleared to “0”, the RAM back-up
mode is selected and the input of INT pin is disabled, be careful
about the following notes.
When the key-on wakeup function of port P13 is not used (regis-
ter K13 = “0”), clear bits 2 and 3 of register I1 before system
enters to the RAM back-up mode. (refer to Figure 48).
LA
0
; (002)
TI1A
; Input of INT disabled ........................
DI
EPOF
POF2
; RAM back-up
: these bits are not used here.
Fig. 48 External 0 interrupt program example-2
Note [3] on bit 2 of register I1
When the interrupt valid waveform of the P13/INT pin is changed
with the bit 2 of register I1 in software, be careful about the fol-
lowing notes.
Depending on the input state of the P13/INT pin, the external 0 in-
terrupt request flag (EXF0) may be set when the bit 2 of register
I1 is changed. In order to avoid the occurrence of an unexpected
interrupt, clear the bit 0 of register V1 to “0” (refer to Figure 49)
and then, change the bit 2 of register I1.
In addition, execute the SNZ0 instruction to clear the EXF0 flag to
“0” after executing at least one instruction (refer to Figure 49).
Also, set the NOP instruction for the case when a skip is per-
formed with the SNZ0 instruction (refer to Figure 49).
LA
4
; (02)
TV1A
; The SNZ0 instruction is valid ...........
LA
12
; (12)
TI1A
; Interrupt valid waveform is changed
NOP
...........................................................
SNZ0
; The SNZ0 instruction is executed
(EXF0 flag cleared)
NOP
...........................................................
: these bits are not used here.
Fig. 49 A/D conversion interrupt program example
LA
4
; (02)
TV1A
; The SNZ0 instruction is valid ...........
LA
8
; (12)
TI1A
; Control of INT pin input is changed
NOP
...........................................................
SNZ0
; The SNZ0 instruction is executed
(EXF0 flag cleared)
NOP
...........................................................
: these bits are not used here.
Fig. 47 External 0 interrupt program example-1
LIST OF PRECAUTIONS
P13/INT pin
Note [1] on bit 3 of register I1
When the input of the INT pin is controlled with the bit 3 of regis-
ter I1 in software, be careful about the following notes.
Depending on the input state of the P13/INT pin, the external 0 in-
terrupt request flag (EXF0) may be set when the bit 3 of register
I1 is changed. In order to avoid the occurrence of an unexpected
interrupt, clear the bit 0 of register V1 to “0” (refer to Figure 47)
and then, change the bit 3 of register I1.
In addition, execute the SNZ0 instruction to clear the EXF0 flag to
“0” after executing at least one instruction (refer to Figure 47).
Also, set the NOP instruction for the case when a skip is per-
formed with the SNZ0 instruction (refer to Figure 47).
Clock control
Execute the CMCK or the CRCK instruction in the initial setting
routine of program (executing it in address 0 in page 0 is recom-
mended).
The oscillation circuit by the CMCK or CRCK instruction can be
selected only at once. The oscillation circuit corresponding to the
first executed one of these two instruction is valid. Other oscilla-
tion circuits and the on-chip oscillator stop.
On-chip oscillator
The clock frequency of the on-chip oscillator depends on the sup-
ply voltage and the operation temperature range.
Be careful that variable frequencies when designing application
products.
Also, the oscillation stabilize wait time after system is released
from reset is generated by the on-chip oscillator clock. When
considering the oscillation stabilize wait time after system is re-
leased from reset, be careful that the variable frequency of the
on-chip oscillator clock.
External clock
When the external signal clock is used as the source oscillation
(f(XIN)), note that the RAM back-up mode (POF2 instructions)
cannot be used.
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