Chapter 7 16-bit Timer

7-6 16-bit Standard PWM Output

(Only duty can be changed consecutively)

The TM7IO pin outputs the standard PWM output, which is determined by the over flow timing of the binary counter, and the match timing of the timer binary counter and the compare register.

7-6-1 Operation

„16-bit Standard PWM Output (Timer 7)

PWM waveform with an arbitrary duty is generated by setting a duty of PWM "H" period to the compare register 1 (TM7OC1). Its cycle is the time of the 16-bit timer full count over flow.

Table 7-6-1 shows the PWM output pin.

Table 7-6-1 PWM Output Pin

PWM output pin

Timer 7

TM7IO output pin

(P14)

„Count Timing of Standard PWM Output (at Normal)(Timer 7)

Count clock

TM7EN flag

Compare register 1

Binary counter

PWM source waveform

TM7IO output (PWM output)

N

0000 0001

N-1 N N+1 N+2

FFFE FFFF 0000 0001

N-1 N N+1

(A)

(B)

(C)

 

Setup time for compare register 1

 

 

PWM basic component (overflow time of the binary counter)

 

Figure 7-6-1 Count Timing of Standard PWM Output (at Normal)

PWM source waveform,

(A)shows "H" till the binary counter reaches the compare register from x'0000'.

(B)shows "L" after the compare match, then the binary counter counts up till the over flow.

(C)shows "H", again if the binary counter becomes overflow.

The PWM output form pins is 1 count clock delay of PWM source waveform. This is happened to correct the output cycle.

16-bit Standard PWM Output VII - 23

Page 283
Image 283
Panasonic F77G, MN101C77C bit Standard PWM Output, PWM Output Pin, „Count Timing of Standard PWM Output at NormalTimer