Datasheet

Table Of Contents
Section 19 14-Bit PWM
Rev. 2.00 Jul. 04, 2007 Page 433 of 692
REJ09B0309-0200
Section 19 14-Bit PWM
This LSI has an on-chip 14-bit pulse width modulator (PWM) with four channels. Connecting the
PWM to the low-pass filter enables the PWM to be used as a D/A converter. The standard PWM
or pulse-division type PWM can be selected by software. Figure 19.1 shows a block diagram of
the 14-bit PWM.
19.1 Features
Choice of four conversion periods
A conversion period of 131,072/φ with a minimum modulation width of 8/φ, a conversion
period of 65,536/φ with a minimum modulation width of 4/φ, a conversion period of 32,768/φ
with a minimum modulation width of 2/φ, or a conversion period of 16,384/φ with a minimum
modulation width of 1/φ, can be selected.
Pulse division method for less ripple
Use of module standby mode enables this module to be placed in standby mode independently
when not used (for details, refer to section 6.4, Module Standby Function).
The standard PWM or pulse-division type PWM can be selected by software.
φ/2
φ/4
φ/8
φ/16
PWM
PWM waveform
generator
Pulse-division type waveform
[Legend]
PWDR:
PWCR:
PWM data register
PWM control register
Standard waveform
Internal data bus
PWDR
AEC
PWCR
PWM waveform
generator
Figure 19.1 Block Diagram of 14-Bit PWM