Fig. 2.10.3 14-Bit Pwm Output Example - Renesas 7200 Series User Manual

FUNCTIONAL DESCRIPTION
2.10 PWM
Set "2C " to DA-H register.
16
b7 b6 b5 b4 b3 b2 b1
[DA-H
0 0 1 0
register]
[DA latch]
These bits decide HIGH level area
of fundamental waveform.
HIGH level area of
=
fundamental waveform
Fundamental
waveform
0.25
14-bit
2C 2B 2A ... 03 02 01 00
PWM output
8-bit
FE FD ... D6
FF
counter
Fundamental waveform of smaller interval
"tm" which is not specified by low-order 6
bits is not changed.
14-bit PWM output
Low-order 6-bit output
of DA latch
Fig. 2.10.3 14-bit PWM output example (f(X
2-66
b0
D
1 1 0 0
H
At writing of DA-L
b13
0 1 0 1 1
0
Minimum
High-order 8-bit
resolution bit
value of DA latch
width 0.25 µ s
µ
s 44
...
D5 D4 D3 02 01
µ
0.25 s
t t t
0 1 2
7220 Group User's Manual
[DA-L register]
At writing of DA-L
b6 b5
0
0 1 0 1 0 0
These bits decide smaller interval "tm" in which HIGH level
area is [HIGH level area of fundamental waveform + τ ].
Waveform of smaller interval "tm" specified by low-order 6 bits
14-bit
2C 2B 2A ... 03 02 01 00
PWM output
8-bit
00 FF
counter
τ = 0.25
µ
44 s
t t t
3 4 5
Repeat period
µ
T = 4096 s
) = 8 MHz)
IN
Set "28 " to DA-L register.
16
b7 b6 b5 b4 b3 b2 b1
1 0 1
Undefined
b0
0
µ
0.25 s 45
...
FE FD D6 D5 D4 D3
t t t t t
59 60 61 62 63
b0
D
0 0 0
L
µ
0.25 s
...
02 01 00