19
19-4
Rev.1.0
Figure 19.2.3 RAM Backup State at Power Outage
Note 1: Power outage is detected by the DC IN
(regulator input) voltage.
Note 2: These pins are used to detect a RAM backup
signal.
Note 3: This pin outputs a high when the power is on
and outputs a low when the power is down.
Note 4:
___
Determined by the input voltage level on SBI
pin or ADnINi pin.
Note 5: A d j u s t t h i s c a p a c i t a n c e t o p r o v i d t h e
necessary processing time in
➁
.
RAM BACKUP MODE
19.2 Example of RAM Backup when Power is Down
19.2.2 RAM Backup State
Shown in Figure 19.2.3 is the power outage RAM backup state of the M32R/E. When the power
supply goes down, the power supply monitor IC starts feeding current from the backup battery to
the M32R/E. Also, the power supply monitor IC's power outage detection pin outputs a low, causing
___
the SBI pin or ADnINi pin input to go low, which generates a RAM backup signal (
➀
in Figure
17.2.3). Whether the power is down or not must be determined with respect to the DC IN (regulator
input) voltage in order to allow for a software processing time at power outage.
To enable RAM backup mode, make the following settings.
(1) Create check data to verify after returning from RAM backup to normal mode whether the
RAM data has been retained normally (
➁
in Figure 19.2.3).
When the power supply to VCC goes down after settings in (1), the voltage applied to the VDD pin
becomes 2.0-3.3 V and voltages applied to all other pins drop to 0 V, and the M32R/E thereby
enters RAM backup mode (
➂
in Figure 19.2.3).
VREFn
SBI
ADnINi
M32R/E
C
Backup battery
VCC
VDD
VBB
VREF
Reference voltage for
power outage detection
Power outage
detection signal
Backup power supply
for power outage
Power supply
monitor IC
VDD
DC IN
Input
Output
Regulator
(5V system)
VCCI
AVCCn
OSC-VCC
OUT
VCCE
(Note 1)
Output
Regulator
(3.3V system)
(Note 3)
(Note 2)
3.3V
0V
(Note 4)
"L"
(Note 5)
2.0V - 3.3V
Example of RAM backup processing
Power goes down (Note 4)
Create check data
for backup RAM
➀
➁
➂
RAM backup mode
0V
0V
0V
0V
Содержание 32172
Страница 20: ... This is a blank page 16 ...
Страница 21: ...1 1 Overview 1 2 Block Diagram 1 3 Pin Functions 1 4 Pin Layout CHAPTER 1 CHAPTER 1 OVERVIEW ...
Страница 44: ...1 1 24 Rev 1 0 This is a blank page Overview 1 4 Pin Layout ...
Страница 58: ...2 2 14 Rev 1 0 This is a blank page CPU 2 6 Data Formats ...
Страница 122: ...4 4 26 Rev 1 0 This is a blank page EIT 4 13 Precautions on EIT ...
Страница 200: ...7 7 6 Rev 1 0 This is a blank page RESET 7 4 Precautions to Be Taken Immediately after Reset ...
Страница 240: ...8 8 40 Rev 1 0 This is a blank page INPUT OUTPUT PORTS AND PIN FUNCTIONS 8 5 Precautions on Input Output Ports ...
Страница 298: ...9 9 58 Rev 1 0 This is a blank page DMAC 9 4 Precautions on Using DMAC ...
Страница 416: ...10 10 118 Rev 1 0 This is a blank page INPUT OUTPUT TIMERS 10 6 TOM Output Related 16 bit Timers ...
Страница 658: ...14 14 16 Rev 1 0 REAL TIME DEBUGGER RTD 14 4 Typical Connection with the Host This is a blank page ...
Страница 718: ...16 16 16 Rev 1 0 This is a blank page D A CONVERTERS 16 3 Functional Description of the D A Converters ...
Страница 766: ...18 18 22 Rev 1 0 WAIT CONTROLLER 18 3 Typical Operation of the Wait Controller This is a blank page ...
Страница 776: ...19 19 10 Rev 1 0 RAM BACKUP MODE 19 4 Exiting RAM Backup Mode Wakeup This is a blank page ...
Страница 777: ...CHAPTER 20 CHAPTER 20 OSCILLATION CIRCUIT 20 1 Oscillator Circuit 20 2 Clock Generator Circuit ...
Страница 782: ...20 20 6 Rev 1 0 OSCILLATION CIRCUIT 20 2 Clock Generator Circuit This is a blank page ...
Страница 856: ...23 23 26 Rev 1 0 This is a blank page ELECTRICAL CHARACTERISTICS 23 6 AC Characteristics ...
Страница 857: ...24 1 A D Conversion Characteristics CHAPTER 24 CHAPTER 24 STANDARD CHARACTERISTICS ...
Страница 859: ...Appendix 1 1 Dimensional Outline Drawing APPENDIX 1 APPENDIX 1 MECHANICAL SPECIFICATIONS ...
Страница 861: ...Appendix 2 1 M32R E Instruction Processing Time APPENDIX 2 APPENDIX 2 INSTRUCTION PROCESSING TIME ...
Страница 865: ...Appendix 3 1 Precautions about Noise APPENDIX 3 APPENDIX 3 PRECAUTIONS ABOUT NOISE ...