HD64F2168 Datasheet, PDF (301/874 Pages) Renesas Technology Corp – Renesas 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 four 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
• Eight resolution settings
The resolution can be set to 1, 2, 64, 128, 256, 1024, 4096, or 16384 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.
• Sixteen operation clocks (by combination of eight resolution settings and two base cycle
settings)
Figure 10.1 shows a block diagram of the PWM (D/A) module.
PWX0
PWX1
Select clock
Internal clock
φ
φ/2, φ/64, φ/128, φ/256,
φ/1024, φ/4096, φ/16384
Clock
Control
logic
Base cycle compare match A
Fine–adjustment pulse addition A
Base cycle compare match B
Fine–adjustment pulse addition B
Comparator A
Comparator B
Base cycle overflow
DACNT
Internal data bus
Bus interface
DADRA
DADRB
DACR
[Legend]
DACR:
DADRA:
DADRB:
DACNT:
PWMX D/A control register (6 bits)
PWMX D/A data register A (15 bits)
PWMX D/A data register B (15 bits)
PWMX D/A counter (14 bits)
Module data bus
Figure 10.1 PWMX (D/A) Block Diagram
PWM1420A_010020021100
Rev. 3.00, 03/04, page 261 of 830