Samsung S3F84B8 manual Interrupt Service Routine Diagram

S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 3 SOFTWARE IMPLEMENTATION

Figure 3-3 shows the flow chart of CMP1/2 interrupt service routine. Due to the cooperation of IH-PWM and comparators integrated in S3F84B8, only a few jobs need to be done in the ISR.

CMP1INT ISR (hard lock)

For surge protection

Start

Clr pending bit

Set P0.4(PWM) to input without pull-up R

PWMCON = 0

End

CMP2INT ISR (soft lock)

For IGBT over voltage protection

Start

Clr pending bit

Not mandatory

End

Figure 3-3 Interrupt Service Routine Diagram

NOTE: When hard lock happens, the PWM returns to the safe value immediately.

When soft lock happens. The PWM returns to the safe value immediately for the current PWM cycle. And the PWMDATA will be reloaded as PWMPDATA, usually a smaller one, from the next cycle on.

FAN work flow BUZ work flow

Start
Power flag = 0?	N
Y
IGBT temp < 55	N
Y
Fan Off	Fan On

Start

Beaming for 0.2s

N	Power flag = 1?
	Y
	Pan flag = 1?	N
	Y
	No pan detected?	Error lasts for 2s?	N
	Y	Y
	Beaming for 0.2s

Figure 3-4 Fan and BUZ Workflow

Figure 3-4 shows the workflow of FAN and BUZ. FAN is always on as the IH cooker is generating heat. Even when the device is powered off by manually setting or system protection, it is still on as long as the IGBT temperature is higher than 55 ℃, in order to prevent the cooker from hot temperature damage.

Buzzer is mainly used for information indication. Besides the first beaming at power on, it only gives alarm when some error lasts for 2sec or no pan is detected after trying 30 times

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