Operation Flow - NEC VR4181 mPD30181 User Manual

18.3 Operation Flow

Set LEDHTSREG
LEDs blinking
Set LEDASTCREG
operation
start condition
Software
Hardware
Note Initial setting for each register must be performed when a power is supplied to device for the first time,
regardless whether LEDs blinking function is used or not.
CHAPTER 18 LED CONTROL UNIT (LED)
Start
Register
Note
initial setting
Set LEDLTSREG
LEDCNTREG
LEDSTOP = 1
LEDCNTREG
LEDENABLE = 1
LEDs blink
No
Auto stop
counter = 0
Yes
LEDENABLE = 0
LEDSTOP = 0
LEDINT = 1
LEDs OFF
End
User's Manual U14272EJ3V0UM
Register initial setting
• LEDHTSREG: 0x0010 (LED ON time available)
• LEDLTSREG: 0x0020 (LED OFF time available)
• LEDCNTREG: 0x0002
• LEDASTCREG: 0x04B0
LED blinking time setting
• LEDHTSREG
Set LED ON time.
• LEDLTSREG
Set LED OFF time.
• LEDASTCREG
Set number of LEDs blinking.
Caution
Setting these registers to 0 is prohibited because it may
cause undefined operation.
LED auto stop setting
• LEDSTOP
Set this bit to enable the LED blink auto stop function.
This setting terminates LED blinking automatically after
blinking time set above has elapaed.
LED blinking operation start
• LEDENABLE
Set this bit to start LED blinking operation.
LED blinking operation
• Supervising the auto stop counter
LED blinking terminates when the auto stop counter reaches 0.
Caution
Setting the LEDENABLE and LEDSTOP bits to 0 is prohibited
because it may cause undefined operation.
LED blinking operation termination
• LEDENABLE
LED blinking operation is terminated by setting 0 to this bit.
LED blinking operation terminate interrupt request generation
• LEDINT
An interrupt request to the ICU is generated when 1 is set to
this bit.
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