NEC PD17062 Manuale Utente

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Peripheral equipment

Peripheral address

Corresponding pin

PWM0

05H

PWM

0

PWM1

06H

PWM

1

PWM2

07H

PWM

2

PWM3

08H

PWM

3

The 

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PD17062 has 4 output pins for 6-bit PWM, which enables varying the duty cycle of the 15.625 kHz pulse

signal in 64 steps.  With this capability, attaching an external lowpass filter to the 

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PD17062 makes it function

as a D/A converter.  The PWM pins can also be used as 1-bit output ports.

When used as a D/A converter, the 

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PD17062 sets the D/A outputs in the output data latches, PWMRs.  These

latches, PWMR0, PWMR1, PWMR2, and PWMR3, are mapped at addresses 05H, 06H, 07H, and 08H, respec-

tively.  They can be read- and write-accessed via the DBF.  Table 17-1 lists the correspondence between the

PWMR addresses and the PWM pins.

Each PWMR consists of 7 bits.  Fig. 17-1 shows the configuration of the PWMR and its correspondence with

the DBF.  The highest bit of the PWMR specifies whether the PWM pin is to be used as a PWM output pin or

an output port.  The other six bits specify the output values of the PWM signal.

Fig. 17-2 shows the waveform output from the PWMR pin.