M37221 Mitsubishi, M37221 Datasheet - Page 31

• Manufacturer Part Number: M37221
• Description: SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER with ON-SCREEN DISPLAY CONTROLLER
• Manufacturer: Mitsubishi

Fig. 27. 14-bit PWM output example (f(X
[DA-H
register]
“H” level area of
fundamental waveform
14-bit
PWM output
8-bit
counter
Fundamental
waveform
b7
0
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
Set “2C
b6 b5 b4 b3 b2 b1
0
2C 2B 2A
FF
1
FE FD … D6
16
[DA latch]
” to DA-H register.
0.25 s 44
0
=
These bits decide “H” level area of
fundamental waveform.
1
width 0.25 s
Minimum
resolution bit
At writing of DA-L
…
b13
1
03 02 01 00
0
D5
0
0
D4
IN
b0
0
t
0
) = 8 MHz)
1
D3
D
High-order 8-bit
value of DA latch
H
0
0.25 s 44
t
…
1
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER
1
02 01
t
1
2
0
00
t
3
b6
These bits decide smaller interval “tm” in which “H” leval
area is [“H” level area of fundamental waveform +
0
b5
t
1
4
0
14-bit
PWM output
8-bit
counter
M37221EF-XXXSP,M37221EFSP
= 0.25 s
t
5
Waveform of smaller interval “tm” specified by low-order 6 bits
Repeat period
T = 4096 s
1
[DA-L register]
0
At writing of DA-L
0
2C 2B 2A
FF
t
59
b0
0
with ON-SCREEN DISPLAY CONTROLLER
FE FD
t
60
0.25 s 45
Undefined
MITSUBISHI MICROCOMPUTERS
b7
…
…
Set “28
b6 b5 b4 b3 b2 b1
t
61
D6
03 02 01 00
1
D5
16
t
62
” to DA-L register.
D4
0
].
D3
t
1
63
…
0
0.25 s
02 01
0
b0
0
00
D
L
31