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M37221M6_03 Datasheet, PDF (30/62 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER with ON-SCREEN DISPLAY CONTROLLER | |||
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MITSUBISHI MICROCOMPUTERS
M37221M6-XXXSP
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER
with ON-SCREEN DISPLAY CONTROLLER
Set â2C16â to DA-H register.
Set â2816â to DA-L register.
b7 b6 b5 b4 b3 b2 b1 b0
[DA-H 0 0 1 0 1 1 0 0 DH
register]
At writing of DA-L
b7 b6 b5 b4 b3 b2 b1 b0
[DA-L register]
1 0 1 0 0 0 DL
Undefined
At writing of DA-L
b13
b6 b5
b0
[DA latch] 0 0 1 0 1 1 0 0 1 0 1 0 0 0
âHâ level area of
fundamental waveform
These bits decide âHâ level area of
fundamental waveform.
Minimum
=
resolution bit
width 0.25µs
! High-order 8-bit
value of DA latch
These bits decide smaller interval âtmâ in which âHâ leval
area is [âHâ level area of fundamental waveform + Ï ].
Fundamental
waveform
0.25 µs !44
14-bit
PWM output 2C 2B 2A ⦠03 02 01 00
8-bit
counter
FF FE FD ⦠D6 D5 D4 D3 ⦠02 01 00
Fundamental waveform of smaller interval
âtmâ which is not specified by low-order 6
bits is not changed.
0.25µs!44
Waveform of smaller interval âtmâ specified by low-order 6 bits
0.25 µs !45
14-bit
PWM output 2C 2B 2A ⦠03 02 01 00
0.25 µs
8-bit
counter
FF FE FD ⦠D6 D5 D4 D3 ⦠02 01 00
Ï = 0.25µs
14-bit PWM output
Low-order 6-bit output
of DA latch
t0
t1
t2
t3
t4
t5
t59 t60 t61 t62 t63
Repeat period
T = 4096µs
Fig. 25. 14-bit PWM output example (f(XIN) = 8 MHz)
29
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