m3819 Renesas Electronics Corporation., m3819 Datasheet - Page 176

• Manufacturer Part Number: m3819
• Description: Mitsubishi 8-bit Single-chip Microcomputer 740 Family / 38000 Series
• Manufacturer: Renesas Electronics Corporation.

2. APPLICATION
Fig. 2.9.13 Control procedure [Status transition upon a power failure]
162
Control procedure : Set the related registers in the order shown below to prepare for a power failure.
N
Recovery processing from a power failure
Set so that a timer interrupt occurs every
second.
Execute the WIT instruction.
Initialization
CPUM
CPUM
CPUM (Address:3B
CPUM (Address:3B
Be concluded the condition
recovered from a power failure?
(Address:3B
(Address:3B
Detect a power failure?
RESET
~ ~
16
16
Y
Y
), bit7
), bit5
16
16
), bit6
), bit4
3819 Group USER’S MANUAL
1(Note)
1(Note)
0
1
N
2.9 Clock generating circuit
Middle-speed mode
When select the main clock f(X
(high-speed mode)
Select the X
Internal system clock : select the low-speed
Main clock f(X
At a power failure, the clock count is perform-
ed during processing the timer interrupts
(occur every second).
Note : Do not switch at the same time.
CIN
IN
-X
) : Stopped
COUT
~ ~
oscillating function
mode f(X
MITSUBISHI MICROCOMPUTER
IN
CIN
)/2
3819 Group
).