MC-78F0712-KIT Renesas Electronics America, MC-78F0712-KIT Datasheet - Page 299

• Manufacturer Part Number: MC-78F0712-KIT
• Description: KIT REF SYSTEM 78K0 UPD78F0712
• Manufacturer: Renesas Electronics America

Specifications of MC-78F0712-KIT

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

19.4 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.
<Action>
software counter that uses a timer, and then initialize the ports.
Note 1
If supply voltage fluctuation is 50 ms or less in vicinity of POC detection voltage
In a system where the supply voltage (V
After releasing the reset signal, wait for the supply voltage fluctuation period of each system by means of a
Notes 1.
POC
2.
), the system may be repeatedly reset and released from the reset status. In this case, the time from
No
If reset is generated again during this period, initialization processing is not started.
A flowchart is shown on the next page.
Figure 19-3. Example of Software Processing After Release of Reset (1/2)
50 ms has passed?
Check stabilization
Change CPU clock
Checking cause
(TMIF51 = 1?)
(set to 50 ms)
of oscillation
of reset
Initialization
processing
Start timer
Reset
Power-on-clear
Yes
Note 2
CHAPTER 19 POWER-ON-CLEAR CIRCUIT
DD
User’s Manual U17890EJ2V0UD
) fluctuates for a certain period in the vicinity of the POC detection
; The internal low-speed oscillation
;
;
;
;
;
;
the reset signal is generated
The cause of reset (power-on-clear, WDT, or LVI)
can be identified by the RESF register.
8-bit timer 51 can operate with the
Source: f
(f
Check the stabilization of oscillation of the X1 input clock by using the
OSTC register.
Change the CPU clock from the internal
the X1 input clock.
TMIF51 = 1: Interrupt request is generated.
Initialization of ports
RL
: Internal
RL
(480 kHz (MAX.))/2
low-speed
oscillation clock oscillation frequency)
7
clock is set as the CPU clock when
compare value 200 = 53 ms
internal low-speed oscillation
low-speed
oscillation clock to
clock.
297