Setup Example - Panasonic F77G User Manual

7-4-2

Setup Example

Event Count Setup Example (Timer 7)
If the falling edge of the TM7IO input pin signal is detected 5 times with using timer 7, an interrupt is
generated. An example setup procedure, with a description of each step is shown below.
Setup Procedure
(1) Stop the counter.
TM7MD1 (x'3F78')
bp4
(2) Set the special function pin to input
mode.
P1DIR (x'3F31')
bp4
(3) Select the condition for timer clear.
TM7MD2 (x'3F79')
bp5
(4) Select the count clock source.
TM7MD1 (x'3F78')
bp1-0
bp3-2
(5) Set the interrupt generation cycle.
TM7PR1 (x'3F75', x'3F74')=x'0004'
: TM7EN = 0
: P1DIR4 = 0
: TM7BCR = 1
: TM7CK1-0 = 10
: TM7PS1-0 = 00
Description
(1) Set the TM7EN flag of the timer 7 mode register
1 (TM7MD1) to "0" to stop timer 7 counting.
(2) Set the P1DIR4 flag of the port 1 direction
control register (P1DIR) to "0" to set P14 pin to
input mode.
If it needs, pull-up resistor should be added.
[ Chapter 4 I/O Ports ]
(3) Set the TM7BCR flag of the timer 7 mode
register 2 (TM7MD2) to "1" to select the
compare match as a clear source of binary
counter.
(4) Select the TM7IO input as a clock source by the
TM7CK1-0 flag of the TM7MD1 register. Also,
select 1/1(no division) as a count clock source
by the TM7PS1-0 flag.
(5) Set the interrupt generation cycle to the timer 7
preset register 1 (TM7PR1). The set value
should be 4, because the counting is 5 times.
At that time, the same value is loaded to the
timer 7 compare register 1 (TM7OC1), and the
timer 7 binary counter (TM7BC) is initialized to
x'0000'.
Chapter 7 16-bit Timer
VII - 17
16-bit Event Count