NEC PD78058 Network Card User Manual


 
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CHAPTER 8 16-BIT TIMER/EVENT COUNTER
8.1 Outline of Timers Incorporated in the
µ
PD78054, 78054Y Subseries
This chapter explains 16-bit timer/event counter. Before that, the timers incorporated into the
µ
PD78054, 78054Y
Subseries and related circuits are outlined below.
(1) 16-bit timer/event counter (TM0)
The TM0 can be used for an interval timer, PWM output, pulse widths measurement (infrared ray remote control
receive function), external event counter, square wave output of any frequency or one-shot pulse output.
(2) 8-bit timers/event counters 1 and 2 (TM1 and TM2)
TM1 and TM2 can be used to serve as an interval timer and an external event counter and to output square
waves with any selected frequency. Two 8-bit timer/event counters can be used as one 16-bit timer/event
counter (See CHAPTER 9 8-BIT TIMER/EVENT COUNTERS 1 AND 2).
(3) Watch timer (TM3)
This timer can set a flag every 0.5 sec. and simultaneously generates interrupt requests at the preset time
intervals (See CHAPTER 10 WATCH TIMER).
(4) Watchdog timer (WDTM)
WDTM can perform the watchdog timer function or generate non-maskable interrupt requests, maskable
interrupt requests and RESET at the preset time intervals (See CHAPTER 11 WATCHDOG TIMER).
(5) Clock output control circuit
This circuit supplies other devices with the divided main system clock and the subsystem clock (See CHAPTER
12 CLOCK OUTPUT CONTROL CIRCUIT).
(6) Buzzer output control circuit
This circuit outputs the buzzer frequency obtained by dividing the main system clock (See CHAPTER 13
BUZZER OUTPUT CONTROL CIRCUIT).