HD64F2145 Datasheet, PDF (267/829 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

Section 10 14-Bit PWM Timer (PWMX)
This LSI has an on-chip 14-bit pulse-width modulator (PWM) timer with two output channels. It
can be connected to an external low-pass filter to operate as a 14-bit D/A converter.
10.1 Features
• Division of pulse into multiple base cycles to reduce ripple
• Two resolution settings
The resolution can be set equal to one or two system clock cycles.
• Two base cycle settings
The base cycle can be set equal to T × 64 or T × 256, where T is the resolution.
• Four operating speeds
• Four operation clocks (by combination of two resolution settings and two base cycle settings)
Figure 10.1 shows a block diagram of the PWM (D/A) module.
PWX0
PWX1
Internal clock
Ø
Ø/2
Select clock
Clock
Control
logic
Base cycle compare match A
Fine–adjustment pulse addition
Base cycle compare match B
Fine–adjustment pulse addition
Comparator A
Comparator B
Base cycle overflow
DACNT
Internal data bus
Bus interface
DADRA
DADRB
DACR
Legend
DACR : PWM D/A control register
DADRA : PWM D/A data register A
DADRB : PWM D/A data register B
DACNT : PWM D/A counter
Module data bus
Figure 10.1 PWM (D/A) Block Diagram
PWM1411A_010020020700
Rev. 2.0, 08/02, page 227 of 788