CMT2380F17
Rev0.1 | 86/347
www.cmostek.com
13 Power Management
The CMT2380F17 supports two power monitor modules, Brown-Out Detector 0 (BOD0) and Brown-Out
Detector 1 (BOD1), and 7 power-reducing modes: Idle mode, Power-down mode, Slow mode, Sub-Clock
mode, RTC mode, Watch mode and Monitor mode.
BOD0 and BOD1 report the chip power status on the flags, BOF0 and BOF1, which provide the capability
to interrupt CPU or to reset CPU by software configured. The seven power-reducing modes provide the
different power-saving scheme for chip application. These modes are accessed through the CKCON0,
CKCON2, CKCON3, CKCON4, CKCON5, PCON0, PCON1, PCON2, PCON3, RTCCR and WDTCR register.
13.1
Brown-Out Detector
In CMT2380F17, there are two Brown-Out Detectors (BOD0 & BOD1) to monitor VDD power. Figure
13
–1 shows the functional diagram of BOD0 and BOD1. BOD0 services the fixed detection level at VDD=1.7V
and BOD1 detects the software selection levels (4.2V/3.7V/2.4V/2.0V) on VDD. Associated flag, BOF0
(PCON1.1), is set when BOD0 meets the detection level. If both of ESF (EIE1.3) and BOF0IE (SFIE.1) are
enabled, a set BOF0 will generate a system flag interrupt. It can interrupt CPU either CPU in normal mode or
idle mode. The BOD1 has the same flag function, BOF1, and same interrupt function. The BOD1 interrupt
also wakes up CPU in power down mode if AWBOD1 (PCON2.7) is enabled.
If BO0RE (PCON2.1) is enabled, the BOD0 event will trigger a system reset and set BOF0 to indicate a
BOD0 Reset occurred. The BOD0 reset restart the CPU either CPU in normal mode or idle mode. BOD1 also
has the same reset capability with associated control bit, BO1RE (PCON2.3). The BOD1 reset also restart
CPU in power down mode if AWBOD1 (PCON2.7) is enabled in BOD1 reset operation.
To reduce power consumption, software may clear EBOD1 (PCON2.2) to disable BOD1 if the BOD1 is
not applied in user application.
1.7V
VDD
Voltage
Comparator
+
-
“
1
”
Load
BOF0
BOD0 Interrupt
BOD0 Reset
PCON0.PD
Enable
(PCON1.1)
BOF0IE
(SFIE.1)
ESF
(EIE1.3)
BO0RE
(PCON2.1)
VDD
Voltage
Comparator
+
-
“
1
”
Load
BOF1
BOD1 Interrupt
BOD1 Reset
PCON0.PD
Enable
(PCON1.2)
BOF1IE
(SFIE.2)
ESF
(EIE1.3)
BO1RE
(PCON2.3)
AWBOD1
(PCON2.7)
0
1
2
3
4.2V
3.7V
2.4V
2.0V
00: 2.0V
01: 2.4V
10: 3.7V
11: 4.2V
BO1S1,0
(PCON2.5~4)
Figure 12-1. BOD0 and BOD1
13.2
Power Saving Mode
13.2.1
Slow Mode
Summary of Contents for CMT2380F17
Page 27: ...CMT2380F17 Rev0 1 27 347 www cmostek com 1 25 Phase Noise...
Page 177: ...CMT2380F17 Rev0 1 177 347 www cmostek com Figure 17 3 PCA Interrupt System...
Page 246: ...CMT2380F17 Rev0 1 246 347 www cmostek com SnMIPS S0MI S1MI 1 P3 3 P4 7...
