M16C28 Datasheet, PDF (55/423 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/Tiny SERIES

M16C/28 Group (M16C/28, M16C/28B)
5. Reset
5.5 Voltage Detection Circuit
Note
VCC=5V is assumed in 5.5 Voltage Detection Circuit.
The voltage detection circuit has the reset level detection circuit and the low voltage detection circuit. The
reset level detection circuit monitors the voltage applied to the VCC pin. The microcomputer is reset if the
reset level detection circuit detects VCC is Vdet3 or below. Use bits VC27 and VC26 in the VCR2 register
to determine whether the individual circuit is enabled.
Use the reset level detection circuit for brown-out reset.
The low voltage detection circuit also monitors the voltage applied to the VCC pin. The low voltage detec-
tion circuit use the VC13 bit in the VCR1 register to detect VCC is above or below Vdet4. The low voltage
detection interrupt can be used in the voltage detection circuit.
RESET
VCR2 Register
b7 b6
CM10 Bit=1
(Stop Mode)
Reset level
detection circuit
+
>Vdet3
E
1 shot
>T
Brown-out Detect Reset
(Hardware Reset 2
Release Wait Time)
td(S-R)
Q
Internal Reset Signal
(“L” active)
VCC
+
>Vdet4
E
Low voltage
detection circuit
Figure 5.4 Low Voltage Detection Circuit Block
Noise Rejection
Low Voltage
Detect Signal
VCR1 Register
b3
VC13 Bit
Rev. 2.00 Jan. 31, 2007 ^{page 35} of 385
REJ09B0047-0200