UPD78F0890GK(A)-GAJ-AX NEC, UPD78F0890GK(A)-GAJ-AX Datasheet - Page 587

• 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

22.4.2 When used as interrupt
(1) When detecting level of supply voltage (V
• When starting operation
• When stopping operation
Either of the following procedures must be executed.
•
•
<1> Mask the LVI interrupt (LVIMK = 1).
<2> Clear bit 2 (LVISEL) of the low-voltage detection register (LVIM) to 0 (detects level of supply voltage
<3> Set the detection voltage using bits 3 to 0 (LVIS3 to LVIS0) of the low-voltage detection level selection
<4> Set bit 7 (LVION) of LVIM to 1 (enables LVI operation).
<5> Use software to wait for an operation stabilization time and minimum pulse width (10
<6> Confirm that “supply voltage (V
<7> Clear the interrupt request flag of LVI (LVIIF) to 0.
<8> Release the interrupt mask flag of LVI (LVIMK).
<9> Clear bit 1 (LVIMD) of LVIM to 0 (generates interrupt signal when the level is detected) (default value).
<10> Execute the EI instruction (when vector interrupts are used).
Figure 22-7 shows the timing of the interrupt signal generated by the low-voltage detector. The numbers in
this timing chart correspond to <1> to <9> above.
When using 8-bit memory manipulation instruction:
Write 00H to LVIM.
When using 1-bit memory manipulation instruction:
Clear LVION to 0.
(V
register (LVIS).
“supply voltage (V
LVIM.
DD
)) (default value).
DD
) < detection voltage (V
CHAPTER 22 LOW-VOLTAGE DETECTOR
DD
User’s Manual U17554EJ4V0UD
) ≥ detection voltage (V
DD
)
LVI
)” when detecting the rising edge of V
LVI
)” when detecting the falling edge of V
DD
μ
s (MAX.)).
, at bit 0 (LVIF) of
DD
587
, or