Fujitsu MB90420/5 (A) Series Hardware Manual page 441

MB90420/5 (A) SERIES F
[bit 3] OE1 : Amplitude output enable bit
When this bit is set to "1", the external pin is assigned as the SGA output. Otherwise the pin can be used
as a general purpose I/O.
The SGA signal is the PWM pulses from the PWM pulse generator representing the amplitude of the
sound.
[bit 2] INTE : Interrupt enable bit
This bit enables the interrupt signal of the sound generator. When this bit is "1" and the INT bit is set to
"1", the sound generator signals an interrupt.
[bit 1] INT : Interrupt bit
This bit is set to "1" when the tone pulse counter counts the count of the tone pulses specified by the tone
count register and decrement grade register.
This bit is reset to "0" by writing "0". Writing "1" has no effect and Read-Modify-Write instructions always
result in reading "1".
[bit 0] ST : Start bit
This bit is for starting the operation of the sound generator. While this bit is "1", the sound generator
perform its operation.
When this bit is reset to "0", the sound generator stops its operation at the end of the current tone cycle.
The BUSY bit indicates whether the sound generator is fully stopped.
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MC-16LX FAMILY 16-BIT MICROCONTROLLERS HARDWARE MANUAL
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