Renesas 4513 Network Card User Manual


 
APPLICATION
2.3 Timers
2-33
4513/4514 Group User’s Manual
Fig. 2.3.4 CNTR0 output setting example
g0 h
0
b3 b0
Disable Interrupts
Timer 1 interrupt is temporarily disabled.
Interrupt enable flag INTE
Interrupt control register V1
“0”
✕✕
All interrupts disabled (DI instruction)
Timer 1 interrupt occurrence disabled
(TV1A instruction)
b3 b0
00
Stop Timer Operation
Timer 1 and prescaler are temporarily stopped.
Dividing ratio of prescaler is selected.
Timer control register W1
Timer 1 stop (TW1A instruction)
Prescaler stop
Prescaler divided by 4 selected
0
Set Timer Value, Select CNTR0 Output
CNTR0 output is selected.
Timer 1 count time is set.
Timer control register W6
Timer 1 reload register R1
“29
16
Timer count value 41 set (T1AB instruction)
b3 b0
1
0
CNTR0 output selected (TW6A instruction)
Clear Interrupt Request
Timer 1 interrupt activated condition is cleared.
Timer 1 interrupt request flag T1F
“0”
Timer 1 interrupt activated condition cleared
(SNZT1 instruction)
Note when the interrupt request is cleared
When is executed, considering the skip of the next instruction according to the
interrupt request flag T1F, insert the NOP instruction after the SNZT1 instruction.
Start Timer 1 Operation
Timer 1 and prescaler temporarily stopped are restarted.
Timer 1 operation start (TW1A instruction)
Prescaler operation start
b3 b0
10
Timer control register W1
1
b3 b0
1
Enable Interrupts
The timer 1 interrupt which is temporarily disabled is enabled.
Interrupt control register V1
Interrupt enable flag INTE
“1”
Timer 1 interrupt occurrence enabled
(TV1A instruction)
All interrupts enabled (EI instruction)
✕✕
b3 b0
0
Stop CNTR0 Output
D6/CNTR0 pin is set to CNTR0 input pin, and it is set to the high-impedance state.
Timer control register W6
Output latch of port D
6 is set to “1.”
CNTR0 input pin set (TW6A instruction)
(SD instruction)
✕✕
0
”: it can be “0” or “1.”