NEC 78014Y Series, User Manual

Page: 188 / 547

www.DataSheet4U.com
188
CHAPTER 8 16-BIT TIMER/EVENT COUNTER
8.5.2 PWM output operations
By setting bits 1 to 3 (TMC01 to 03) of the 16-bit timer mode control register (TMC0) to 1, 0, and 0, they are operated
as PWM output. Pulses with the duty rate determined by the value set in 16-bit compare register (CR00) beforehand
are output from the TO0/P30 pin.
Set the active level width of the PWM pulse to the high-order 14 bits of CR00. Select the active level with bit 1
(TOC01) of the 16-bit timer output control register (TOC0).
This PWM pulse has a 14-bit resolution. The pulse can be converted to an analog voltage by integrating it with
an external low-pass filter (LPF). The PWM pulse has a combination of the basic cycle determined by 2
8
/f
Φ
and the
sub-cycle determined by 2
14
/f
Φ
so that the time constant of the external LPF can be shortened. Count clock f
Φ
can
be selected with bits 4 to 6 (TCL04 to TCL06) of the timer clock select register 0 (TCL0).
PWM output enable/disable can be selected with bit 0 (TOE0) of TOC0.
Cautions 1. PWM operation mode should be selected before setting CR00.
2. Be sure to write 0 to bits 0 and 1 of CR00.
3. Do not select PWM operation mode for external clock input from the INTP0/P00/TI0 pin.