UPD78F0890GK(A)-GAJ-AX NEC, UPD78F0890GK(A)-GAJ-AX Datasheet - Page 582

• 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

22.4.1 When used as reset
(1) When detecting level of supply voltage (V
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• 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> Wait until it is checked that (supply voltage (V
<7> Set bit 1 (LVIMD) of LVIM to 1 (generates reset when the level is detected).
Figure 22-5 shows the timing of the internal reset signal generated by the low-voltage detector. The numbers
in this timing chart correspond to <1> to <7> above.
Cautions 1. <1> must always be executed. When LVIMK = 0, an interrupt may occur immediately
When using 8-bit memory manipulation instruction:
Write 00H to LVIM.
When using 1-bit memory manipulation instruction:
Clear LVIMD to 0 and then LVION to 0.
(V
register (LVIS).
DD
)) (default value).
2. If supply voltage (V
after the processing in <4>.
reset signal is not generated.
CHAPTER 22 LOW-VOLTAGE DETECTOR
User’s Manual U17554EJ4V0UD
DD
) ≥ detection voltage (V
DD
)
DD
) ≥ detection voltage (V
LVI
) when LVIMD is set to 1, an internal
LVI
)) by bit 0 (LVIF) of LVIM.
μ
s (MAX.)).