Mitsubishi microcomputers
M16C / 62P Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Reset
28
development
Preliminary Specifications Rev.1.0
Specifications in this manual are tentative and subject to change.
2. Limitations on WAIT Instruction
If the WAIT instruction is executed when the VC13 bit in the VCR1 register is “1” (V
CC1
≥
Vdet4) while the
VC27 bit in the VCR2 register is “1” (power supply down detection circuit enable) and the D40 bit in the
D4INT register is “1” (power supply down detection interrupt enable), a power supply down detection
interrupt is immediately generated, causing the microcomputer to exit wait mode.
In systems where the microcomputer enters wait mode when the input voltage at the V
CC1
pin drops
below Vdet4 and exits wait mode when the input voltage rises to Vdet4 or more, make sure the WAIT
instruction is executed when VC13 bit is “0” (V
CC1
< Vdet4).
Figure 1.5.8. Power Supply Down Detection Interrupt Generation Block
Power supply down detection interrupt generation circuit
Oscillation stop,
re-oscillation
detection
interrupt signal
Watchdog timer block
This bit is set to “0”(not detected) by writing a “0” in a program.
D43
D41
WAIT instruction(waiCM02
D40
VC27
V
CC1
V
REF
+
-
(Rejection wide:200 ns)
VC13
“H” when VC27
bit= 0 (disabled)
Noise rejection
circuit
Digital
filter
BCLK
D42
DF1, DF0
1/2
00
2
01
2
10
2
11
2
1/2
1/2
1/8
Noise
rejection
Power supply
down
detection
signal
Watchdog timer
underflow signal
D42 bit is set to “0”(not detected) by
writing a “0” in a program. VC27 bit
is set to “0” (power supply down
detection circuit disabled), the D42
bit is set to “0”.
Power supply down detection circuit
Power supply
down detection
interrupt signal
Watchdog
timer interrupt
signal
Non-maskable
interrupt signal
Figure 1.5.9. Power Supply Down Detection Interrupt Generation Circuit Operation Example
Output of the digital filter (Note 2)
D42 bit
Note 1 : D40 is “1”(power supply down
detection interrupt enabled)
Note 2 : Output of the digital filter shown in Figure 1.5.8.
Power supply down
detection
interrupt signal
No power supply down detection interrupt signals
are generated when the D42 bit is “H”.
sampling
Set to “0” in a
program
(not
detected)
VC13 bit
V
CC1
sampling
sampling
sampling
Set to “0” in a
program
(not
detected)