Voltage Detection Circuit - Renesas M16C/29 Series Hardware Manual

M16C/29 Group

5.5 Voltage Detection Circuit

Note
5.5 Voltage Detection Circuit is described in the Normal-ver. only as an example.
This is assumed to use when VCC = 5V. Do not use this function in the T-ver. and V-ver.
The voltage detection circuit monitors the voltage applied to the VCC pin in Vdet3 and Vdet 4. The VC26 to
VC27 bits in the VCR2 register determine whether this circuit is enabled or disabled.
The reset level detect circuit is required for the voltage down detection reset (hardware reset 2) .
The voltage down detection circuit detects whether VCC is more than or less than Vdet4. The VC13 bit in
the VCR1 register determines the detection result. The voltage detect interrupt is available.
Figure 5.5.1 shows a voltage detection circuit Block
R E S E T
CM10 Bit=1
(Stop Mode)
V C C
Figure 5.5.1 Voltage Detection Circuit Block
Rev.1.00 Nov 01,2004
REJ09B0101-0100Z
V C R 2 R e g i s t e r
b7 b6
page 31 of 402
Write to WDC register
Internal power on reset
+
≥Vdet3
E
+
≥Vdet4
Noise Rejection
E
WDC5 Bit
S Q WARM/COLD
(Cold start, warm start)
R
Voltage Down Detect Reset
(Hardware Reset 2
1 shot
Release Wait Time)
t d ( S - R )
>T
Q
I n t e r n a l R e s e t S i g n a l
( " L " a c t i v e )
V o l t a g e D o w n
D e t e c t S i g n a l
V C R 1 R e g i s t e r
b 3
VC13 Bit
5. Reset