NEC PD78F9488 Manuale Utente

120

User’s Manual U15331EJ4V1UD

CHAPTER 7 8-BIT TIMERS 50, 60, AND 61

7.1 Functions of 8-Bit Timers 50, 60, and 61

One 8-bit timer channel (timer 50) and two 8-bit timer/event counter channels (timer 60 and 61) are incorporated in

the

PD789489 Subseries. The operation modes listed in the following table can be set via mode register settings.

Table 7-1. Operation Modes

Channel

Mode

Timer 50

Timer 60

Timer 61

8-bit timer counter mode
(stand-alone mode)

Available Available Available

16-bit timer counter mode
(cascade connection mode)

Available Not

available

Carrier generator mode

Available Not

available

PWM output mode

Available

Not available

PPG output mode

Not available Available Available

24-bit event counter mode
(connect with 16-bit timer 20)

Not available

Not available Available

(1) Mode to use 8-bit timer/event counter as discrete unit (stand-alone mode)

The following functions can be used in this mode.
<Timer 50>

• Interval timer with 8-bit resolution
• Square wave output with 8-bit resolution

•  Interval timer with 8-bit resolution
•  External event counter with 8-bit resolution
•  Square wave output with 8-bit resolution

(2) Mode to use timer 50 and timer 60 connected in cascade (16-bit resolution: cascade connection)

Operation as a 16-bit timer/event counter is enabled in cascade connection mode.
The following functions can be used in this mode.

•  Interval timer with 16-bit resolution
•  External event counter with 16-bit resolution
•  Square wave output with 16-bit resolution

(3) Carrier generator mode

The carrier clock generated by timer 60 is output in the cycle set by timer 50.

(4) PWM output mode (PWM: Pulse Width Modulator)

Pulses are output using any duty ratio (pulse width). The cycle (overflow cycle of the timer) becomes
constant (free running).