Mitsubishi microcomputers
M16C / 61 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Interrupt
Time (a) is dependent on the instruction under execution. Thirty cycles is the maximum required for the
DIVX instruction (without wait).
Time (b) is as shown in Table 1.13.5.
Table 1.13.5. Time required for executing the interrupt sequence
Interrupt vector address Stack pointer (SP) value
16-Bit bus, without wait
8-Bit bus, without wait
Even
Even
Odd
18 cycles (Note 1)
19 cycles (Note 1)
19 cycles (Note 1)
20 cycles (Note 1)
20 cycles (Note 1)
20 cycles (Note 1)
20 cycles (Note 1)
20 cycles (Note 1)
Even
Odd (Note 2)
Odd (Note 2)
Even
Odd
________
Note 1: Add 2 cycles in the case of a DBC interrupt; add 1 cycle in the case either of an address coincidence
interrupt or of a single-step interrupt.
Note 2: Locate an interrupt vector address in an even address, if possible.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
BCLK
Address
0000
Address bus
Data bus
Indeterminate
Indeterminate
SP-2
SP-4
vec
vec+2
PC
Interrupt
information
SP-2
SP-4
vec
vec+2
contents contents contents contents
R
Indeterminate
W
The indeterminate segment is dependent on the queue buffer.
If the queue buffer is ready to take an instruction, a read cycle occurs.
Figure 1.13.5. Time required for executing the interrupt sequence
Variation of IPL when Interrupt Request is Accepted
If an interrupt request is accepted, the interrupt priority level of the accepted interrupt is set in the IPL.
If an interrupt request, that does not have an interrupt priority level, is accepted, one of the values shown
in Table 1.13.6 is set in the IPL.
Table 1.13.6. Relationship between interrupts without interrupt priority levels and IPL
Value set in the IPL
Interrupt sources without priority levels
_______
Watchdog timer, NMI
7
0
Reset
Other
Not changed
50
MITSUBISHI [ Mitsubishi Group ]
