17
17-8
RAM BACKUP MODE
32180 Group User's Manual (Rev.1.0)
17.4 Exiting RAM Backup Mode (Wakeup)
17.4 Exiting RAM Backup Mode (Wakeup)
The processing to place the M32R/ECU out of RAM backup mode and return it to normal operation mode is
referred to as “wakeup” processing. Figure 17.4.1 shows an example of wakeup processing.
Wakeup processing is initiated by applying a reset. The following shows how to execute wakeup processing.
(1) Reset the microcomputer ((a) in Figure 17.4.1).
(2) Set port X for output mode and output a high from the port ((b) in Figure 17.4.1) (Note 1)
(3) Compare the RAM content against the RAM check data created before entering RAM backup mode ((c) in
Figure 17.4.1).
(4) If the comparison in (3) did not match, initialize the RAM ((d) in Figure 17.4.1).
If the comparison in (3) matched, use the retained data in the program.
(5) Initialize each internal circuit ((e) in Figure 17.4.1) before returning to the main routine ((f) in Figure 17.4.1).
Note 1: For wakeup from power outage RAM backup mode, port X settings are unnecessary.
Figure 17.4.1 Wakeup Processing
OK
Error
Compare RAM content
against backup RAM
check data
Initialize the RAM
Example of wakeup processing
Reset
Set the transistor's base
connecting pin (port X)
for high-level output mode
(Note 1)
Initialize each circuit
To the main routine
(a)
(b)
(c)
(d)
(e)
(f)
Note 1: For wakeup from power outage RAM backup mode, port X settings are unnecessary.
Содержание M32R/ECU Series
Страница 17: ...12 This page is blank for reasons of layout...
Страница 18: ...CHAPTER 1 OVERVIEW 1 1 Outline of the 32180 Group 1 2 Block Diagram 1 3 Pin Functions 1 4 Pin Assignments...
Страница 712: ...CHAPTER 18 OSCILLATOR CIRCUIT 18 1 Oscillator Circuit 18 2 Clock Generator Circuit...
Страница 794: ...CHAPTER 22 TYPICAL CHARACTERISTICS...
Страница 795: ...22 22 2 32180 Group User s Manual Rev 1 0 TYPICAL CHARACTERISTICS To be written at a later time...
Страница 796: ...APPENDIX 1 MECHANICAL SPECIFICAITONS Appendix 1 1 Dimensional Outline Drawing...
Страница 798: ...APPENDIX 2 INSTRUCTION PROCESSING TIME Appendix 2 1 32180 Instruction Processing Time...
Страница 802: ...APPENDIX 3 PROCESSING OF UNUSED PINS Appendix 3 1 Example Processing of Unused Pins...