UPD78F0537DGA(T)-9EV-A NEC, UPD78F0537DGA(T)-9EV-A Datasheet - Page 544

• Manufacturer Part Number: UPD78F0537DGA(T)-9EV-A
• Description: 8BIT MCU, 128K FLASH, 7KB RAM, SMD
• Manufacturer: NEC

Specifications of UPD78F0537DGA(T)-9EV-A

• Controller Family/series: UPD78
• No. Of I/o's: 55
• Ram Memory Size: 7KB
• Cpu Speed: 20MHz
• No. Of Timers: 8
• No. Of Pwm: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 128KB
• Oscillator Type: External, Internal

23.4 Cautions for Power-on-Clear Circuit
voltage (V
release of reset to the start of the operation of the microcontroller can be arbitrarily set by taking the following action.
544
Note 1
In a system where the supply voltage (V
<Action>
• If supply voltage fluctuation is 50 ms or less in vicinity of POC detection voltage
Notes 1.
After releasing the reset signal, wait for the supply voltage fluctuation period of each system by means of a
software counter that uses a timer, and then initialize the ports.
POC
2.
), the system may be repeatedly reset and released from the reset status. In this case, the time from
If reset is generated again during this period, initialization processing <2> is not started.
A flowchart is shown on the next page.
No
Figure 23-3. Example of Software Processing After Reset Release (1/2)
Setting 8-bit timer H1
(to measure 50 ms)
50 ms has passed?
processing <1>
processing <2>
(TMIFH1 = 1?)
Clearing WDT
Initialization
Initialization
Reset
Yes
Power-on-clear
CHAPTER 23 POWER-ON-CLEAR CIRCUIT
DD
User’s Manual U17260EJ6V0UD
) fluctuates for a certain period in the vicinity of the POC detection
;
; f
; Setting of division ratio of system clock,
Check the reset source
Initialize the port.
Source: f
Timer starts (TMHE1 = 1).
such as setting of timer or A/D converter
PRS
= Internal high-speed oscillation clock (8.4 MHz (MAX.)) (default)
where comparison value = 102: ≅ 50 ms
PRS
(8.4 MHz (MAX.))/2
Note 2
12
,