UPD78F0890GK(A)-GAJ-AX NEC, UPD78F0890GK(A)-GAJ-AX Datasheet - Page 593

• Manufacturer Part Number: UPD78F0890GK(A)-GAJ-AX
• Description: 8BIT MCU, 128K FLASH, 7K RAM, LQFP
• Manufacturer: NEC

Specifications of UPD78F0890GK(A)-GAJ-AX

• Controller Family/series: UPD78F
• No. Of I/o's: 55
• Ram Memory Size: 7KB
• Cpu Speed: 20MHz
• No. Of Timers: 10
• No. Of Pwm: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 128KB
• Oscillator Type: External, Internal

• If supply voltage fluctuation is 50 ms or less in vicinity of LVI detection voltage
Note
A flowchart is shown on the next page.
No
(TMHE1 = 0
Setting 8-bit timer H1
Figure 22-9. Example of Software Processing After Reset Release (1/2)
(to measure 50 ms)
50 ms has passed?
Restarting timer H1
voltage or higher
processing <1>
processing <2>
(TMIFH1 = 1?)
Clearing WDT
Initialization
Initialization
(LVIF = 0?)
Setting LVI
Detection
LVIF = 0
Reset
No
Yes
TMHE1 = 1)
LVI reset
CHAPTER 22 LOW-VOLTAGE DETECTOR
Yes
User’s Manual U17554EJ4V0UD
;
; Setting of detection level by LVIS
; Setting of division ratio of system clock,
; f
;
; The timer counter is cleared and the timer is started.
Check the reset source
Initialize the port.
The low-voltage detector operates (LVION = 1).
Source: f
Timer starts (TMHE1 = 1).
such as setting of timer or A/D converter
The low-voltage detection flag is cleared.
PRS
= Internal high-speed oscillation clock (8.4 MHz (MAX.)) (default)
Where comparison value = 102:
PRS
(8.4 MHz (MAX.))/2
Note
12
,
50 ms
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