M37754 Mitsubishi, M37754 Datasheet - Page 20

• Manufacturer Part Number: M37754
• Description: SINGLE-CHIP 16BIT CMOS MICROCOMPUTER
• Manufacturer: Mitsubishi

As shown in Figure 13, there are three different interrupt priority de-
tection time from which one is selected by software. After the se-
lected time has elapsed, the highest priority is determined and is
processed after the currently executing instruction has been com-
pleted.
The time is selected with bits 4 and 5 of the processor mode register
0 (address 5E
between these bits and the number of cycles. After a reset, the pro-
cessor mode register 0 is initialized to “00
time is automatically set, however, the shortest time must be se-
lected by software.
Fig. 13 Interrupt priority detection time
20
16
Operation code fetch cycle
Sampling pulse
Priority detection time
Select one from 0 to 2 with
bits 4 and 5 of processor
mode register 0
) shown in Figure 14. Table 5 shows the relationship
BIU
16.
” Therefore, the longest
0
1
2
M37754M8C-XXXGP, M37754M8C-XXXHP
Table 4. Value set in processor interrupt level (IPL) during an interrupt
Table 5. Relationship between interrupt priority detection time select
Priority detection time select bit
____
Reset
DBC
Watchdog timer
Zero divide
BRK instruction
M37754S4CGP, M37754S4CHP
Interrupt types
Bit 5
0
0
1
bit and number of cycles
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Bit 4
MITSUBISHI MICROCOMPUTERS
0
1
0
Not change value of IPL.
Not change value of IPL.
Setting value
Number of cycles
7 cycles of
4 cycles of
2 cycles of
0
7
7
BIU
BIU
BIU