Panasonic F77G, MN101C77C user manual Output Waveform of TM7IO Output Pin

Models: F77G MN101C77C

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Chapter 7 16-bit Timer

7-6-2 Setup Example

„Standard PWM Output Setup Example (Timer 7)

The TM7IO output pin outputs the 1/4 duty PWM output waveform at 305.18 Hz with timer 7. The high frequency oscillation (fosc) is set to be operated at 20 MHz. One cycle of the PWM output waveform is decided by the overflow of a binary counter. "H" period of the PWM output waveform is decided by the set value of a compare register 1.

An example setup procedure, with a description of each step is shown below.

TM7IO output

305.18 Hz

Figure 7-6-4 Output Waveform of TM7IO Output Pin

 

Setup Procedure

 

 

 

Description

 

 

 

 

 

(1)

Stop the counter.

 

(1)

Set the TM7EN flag of the timer 7 mode

 

TM7MD1 (x'3F78')

 

 

register 1 (TM7MD1) to "0" to stop timer 7

 

bp4

: TM7EN

= 0

 

counting.

 

(2)

Set the special function pin to output

(2)

Set the P1OMD4 flag of the port 1 output mode

 

mode.

 

 

 

register (P1OMD) to "1" to set the P14 pin as a

 

P1OMD (x'3F2F')

 

 

special function pin. Set the P1DIR4 flag of the

 

bp4

: P1OMD4

= 1

 

port 1 direction control register (P1DIR) to "1"

 

P1DIR (x'3F31')

 

 

to set output mode. Add pull-up resistor, if it

 

bp4

: P1DIR4

= 1

 

necessary.

 

 

 

 

 

[

Chapter 4 I/O Ports ]

(3)

Set the PWM output.

 

(3)

Set the TM7PWM flag of the timer 7 mode

 

TM7MD2 (x'3F79')

 

 

register 2 (TM7MD2) to "1" to select the PWM

 

bp4

: TM7PWM = 1

 

output.

 

(4)

Set the standard PWM output

(4)

Set the TM7BCR flag of the TM7MD2 register

 

operation.

 

 

 

to "0" to select the full count over flow as a

 

TM7MD2 (x'3F79')

 

 

binary counter clear source.

 

bp5

: TM7BCR

= 0

 

 

 

 

 

 

 

 

 

 

16-bit Standard PWM Output VII - 25

Page 285
Image 285
Panasonic F77G, MN101C77C user manual Output Waveform of TM7IO Output Pin