Renesas 4514 Manual De Usuario

2-22

4513/4514 Group User’s Manual

0

b3

b0

➀

 Disable Interrupts

Timer 2 interrupt is temporarily disabled.

Interrupt enable flag INTE

Interrupt control register V1

“0”

✕ ✕ ✕

All interrupts disabled (DI instruction)

Timer 2 interrupt occurrence disabled 
(TV1A instruction)

b3

b0

0

1

1

➁

 Stop Timer Operation

Timer is temporarily stopped.
Timer 2 count source is selected.

Timer control register W2

✕

Timer 2 stop (TW2A instruction)
16-bit timer (WDT) underflow signal selected
for count source 

➂

 Set Timer Value

Timer 2 count time is set. (The formula is shown 

❈

A below.)

Timer 2 reload register R2 “27

16

”

Timer count value 39 set (T2AB instruction)

➃

 Clear Interrupt Request

Timer 2 interrupt activated condition is cleared.

Timer 2 interrupt request flag T2F “0”

Timer 2 interrupt activated condition cleared 
(SNZT2 instruction)

Note when the interrupt request is cleared

When 

➃

 is executed, considering the skip of the next instruction according to the 

interrupt request flag T2F, insert the NOP instruction after the SNZT2 instruction.

b3

b0

1

1

1

➄

 Start Timer 2 Operation

Timer 2 temporarily stopped is restarted.

Timer control register W2

Timer 2 operation start (TW2A instruction)

✕

b3

b0

1

➅

 Enable Interrupts

The timer 2 interrupt which is temporarily disabled is enabled.

AAAAAAA

AAAAAAA

Interrupt control register V1

Interrupt enable flag INTE

“1”

Timer 2 interrupt occurrence enabled 
(TV1A instruction)
All interrupts enabled (EI instruction)

✕ ✕ ✕

Constant period interrupt execution start

❈

A The timer 2 count value to make the interrupt occur every about 2 s is set as follows.

2 s 

≅

 (4.0 MHz)

✕

  3

✕

2

✕

(39+1)

–1

System clock Instruction 

clock

16-bit 
fixed 
dividing 
frequency

Timer 2
count 
value

16

“

✕

”: it can be “0” or “1.”