UPD78F0890GK(A)-GAJ-AX NEC, UPD78F0890GK(A)-GAJ-AX Datasheet - Page 590

• 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

(2) When detecting level of input voltage from external input pin (EXLVI)
590
• When starting operation
• When stopping operation
Either of the following procedures must be executed.
•
<1> Mask the LVI interrupt (LVIMK = 1).
<2> Set bit 2 (LVISEL) of the low-voltage detection register (LVIM) to 1 (detects level of input voltage from
<3> Set bit 7 (LVION) of LVIM to 1 (enables LVI operation).
<4> Use software to wait for an operation stabilization time and minimum pulse width (10
<5> Confirm that “input voltage from external input pin (EXLVI) ≥ detection voltage (V
<6> Clear the interrupt request flag of LVI (LVIIF) to 0.
<7> Release the interrupt mask flag of LVI (LVIMK).
<8> Clear bit 1 (LVIMD) of LVIM to 0 (generates interrupt signal when the level is detected) (default value).
<9> Execute the EI instruction (when vector interrupts are used).
Figure 22-8 shows the timing of the interrupt signal generated by the low-voltage detector. The numbers in
this timing chart correspond to <1> to <8> above.
•
Caution Input voltage from external input pin (EXLVI) must be EXLVI < V
When using 8-bit memory manipulation instruction:
Write 00H to LVIM.
When using 1-bit memory manipulation instruction:
Clear LVION to 0.
external input pin (EXLVI)).
when detecting the falling edge of EXLVI, or “input voltage from external input pin (EXLVI) < detection
voltage (V
EXLVI
= 1.21 V (TYP.))” when detecting the rising edge of EXLVI, at bit 0 (LVIF) of LVIM.
CHAPTER 22 LOW-VOLTAGE DETECTOR
User’s Manual U17554EJ4V0UD
DD
.
EXLVI
μ
s (MAX.)).
= 1.21 V (TYP.)”