NEC V850E/Dx3 Preliminary User's Manual page 851

Sound Generator (SG)
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Note To achieve 100 % duty cycle for all PWM frequencies, SGOFL must not be set
to a value above 1FE
The PWM signal is continually low when the value of the volume buffer is
zero—the sound has stopped.
(1) Updating the volume buffer value
The value of the volume compare buffer can be changed by writing to the
volume register SG0PWM.
• If the register is cleared by writing 0000
volume compare buffer with the next rising edge of SG0CLK.
• As a result, the sound stops at the latest after one period of SG0CLK.
• If a non-zero value is written to the register, the buffer is updated with the
next falling or rising edge of the tone frequency (match between SG0FH
counter value and SG0FH buffer value).
Preliminary User's Manual U17566EE1V2UM00
.
H
, the register value is copied to the
H
Chapter 24
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