M37702M2AXXXFP Datasheet, PDF (14/59 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

MITSUBISHI MICROCOMPUTERS
M37702M2AXXXFP, M37702M2BXXXFP
M37702S1AFP, M37702S1BFP
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
As shown in Figure 9, there are three different interrupt priority
resolution time from which one is selected by software. After the
selected time has elapsed, the highest priority is determined and
is processed after the currently executing instruction has been
completed.
The time is selected with bits 4 and 5 of the processor mode reg-
ister (address 5E16) shown in Figure 10. Table 4 shows the
relationship between these bits and the number of cycles. After a
reset, the processor mode register is initialized to “0016” and
therefore, the longest time is selected.
However, the shortest time should be selected by software.
Table 3. Value set in processor interrupt level (IPL) during an
interrupt
Interrupt types
Setting value
Reset
0
____
DBC
7
Watchdog timer
7
Zero divide
Not change value of IPL.
BRK instruction
Not change value of IPL.
Table 4. Relationship between priority level resolution time
selection bit and number of cycles
Priority level resolution time selection bit
Bit 5
Bit 4
0
0
0
1
1
0
φ : internal clock
Number of cycles
7 cycles of φ
4 cycles of φ
2 cycles of φ
Internal clock φ
Operation code fetch cycle
Sampling pulse
Priority resolution time
0
Select from 0 to 2 with bits 1
4 and 5 of the processor
mode register
2
Fig. 9 Interrupt priority resolution time
76543210
0
Fig. 10 Processor mode register configuration
Processor mode register (5E 16)
Processor mode bits
0 0 : Single-chip mode
0 1 : Memory expansion mode
1 0 : Microprocessor mode
1 1 : Evaluation chip mode
Wait bit
0 : Wait
1 : No wait
Software reset bit
The processor is reset when this bit is set to “1” .
Priority resolution time selection bits
0 0 : Select 0 in Figure 9
0 1 : Select 1 in Figure 9
1 0 : Select 2 in Figure 9
Test mode bit
Must be “0”
Clock φ1 output selection bit
0 : No φ1 output
1 : φ1 output
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