7220 Datasheet, PDF (90/303 Pages) Renesas Technology Corp – 8-BIT SINGLE-CHIP MICROCOMPUTER

FUNCTIONAL DESCRIPTION
2.10 PWM
2.10 PWM
The M37221M6-XXXSP/FP has one 14-bit PWM (pulse width modulator) [DA], and six 8-bit PWM [PWM0–
PWM5].
Table 2.10.1 shows the PWM function performance.
Table 2.10.1 PWM function performance (at oscillation frequency = 8 MHz)
Performance
14-bit PWM [DA]
Resolution (bits)
14
Minimum resolution bit width (µs)
0.25
Repeat cycle (µs)
4096
8-bit PWM
8
4
1024
Figure 2.10.1 shows the 14-bit PWM block diagram and Figure 2.10.2 shows the 8-bit PWM block diagram.
Data bus
DA-H register
(Address : 00CE16)
b7
b0
DA latch
(14 bits)
MSB
DA-L register (Note)
(Address : 00CF16)
LSB
8
14
6
6
PN2
PN4
DA
14-bit PWM circuit
D-A
PW1
XIN 1/2
PW0
PWM timing
generating
circuit
Selection gate :
Connected to
black side when
reset.
Pass gate
Inside of
with the others.
PW: PWM output control register 1
PN: PWM output control register 2
Note: The DA-L register also functions as the low-order 6 bits of the DA latch.
Fig. 2.10.1 14-bit PWM (DA) block diagram
7220 Group User’s Manual
2-63