Setup Example - Panasonic MN101L Series User Manual

Chapter 9
16-bit Timer
9.8.2

Setup Example

Capture Function Setup Example
Here is an example that, using Timer 7, the value of the binary counter is loaded to the capture register at the
interrupt generation edge of IRQ0 signal to measure the pulse width. The rising edge is selected for the interrupt
generation edge and capture trigger generation edge.
The following is an example of setup procedures.
Figure:9.8.5 Pulse Width Measurement of External Interrupt 0 Input Signal
Step Setting
1 Disable the timer counter
2 Disable the interrupt
3 Set the timer mode register
4
5 Set the compare register
6 Set the timer mode register
7
Set the external interrupt
8
9 Set the timer mode register
10 Set the external interrupt
11 Set the interrupt level
12 Enable the interrupt
13 Set the timer mode register
14 Enable the timer counter
TM7BC counts up from "0x0000". Synchronizing with the External Interrupt 0 input signal, the value of TM7BC
is loaded to TM7IC.
At that time, the pulse width from a rising edge of the external interrupt input signal to the next rising edge can be
measured by reading the value of TM7IC through the interrupt process and calculating the difference between that
value and the last capture value (the last value of TM7IC).
IX - 46 16-bit Timer Capture Function
External Interrupt 0
IRQ0 input
Register
TM7MD.TM7EN = 0
TM7ICR.TM7IE = 0
TM7MD2.TM7BCR = 1
TM7MD1.TM7CK1-0 = 00
TM7MD1.TM7PS1-0 = 00
TM7PR1 = 0xFFFF
TM7MD2.T7ICT1-0 = 00
TM7MD1.T7ICEDG1 = 1
TM7MD2.T7ICEDG0 = 1
IRQISEL0.IRQ0SEL = 0
IRQIEN.IRQI0EN = 1
TM7MD3.TM7CKSMP = 0
IRQ0ICR.REDG0 = 1
IRQ0ICR.IRQ0LV1-0
IRQ0ICR.IRQ0IE = 1
TM7MD2.T7ICEN = 1
TM7MD1.TM7EN = 1
interrupt interrupt
processing processing
Pulse width to be measured
Description
Disable the timer count operation.
Disable the timer interrupt.
Select the TM7BC clear source.
Select HCLK as the count clock source.
Setup data in TM7PR1 is loaded to TM7OC1.
Select the capture trigger source.
Select the capture trigger edge.
Enable the external interrupt pin.
Select the count clock for capture sampling.
Set the external interrupt valid edge.
Refer to [3.1.3 Maskable Interrupt Control Register Setup].
Enable the capture trigger function
Enable the timer count operation.