W78E378 Datasheet, PDF (25/38 Pages) Winbond – MONITOR MICROCONTROLLER

Preliminary W78E378/W78C378/W78C374
Parabola Interrupt Generator
The parabola interrupt generator is a 13-bit auto-reload timer, which generates an interrupt to the
CPU periodically for software to load the parabola waveform data to the dynamic DACs
(DAC8−DAC10). The software should calculate the value of the PARAH and PARAL registers by:
(Vcount × 16) ÷ segment number. The segment number is the number of integration segments
between two Vsync pulses. The interrupt interval is programmable:
• Time base = 1/Fosc
• Programmable interrupt period = Time base × (PARAH × 256 + PARAL + 1)
• Maximum period = Time base × 8192
Note: Zero value in [PARAH, PARAL] is inhibited.
A-to-D Converter (ref. Application Note in Appendix A.)
One 4-bit Analog-to-Digital Converter.
• Conversion time = (6/Fosc) × 128 sec.
• 7 channels selected by an analog multiplexer
(ADCS2, ADCS1, ADCS0) (0, 0, 0) (0, 0, 1) (0, 1, 0) (0, 1, 1) (1, 0, 0) (1, 0, 1) (1, 1, 0)
Selected Channel
ADC0 ADC1 ADC2 ADC3 ADC4 ADC5 ADC6
The conversion of the ADC is started by setting bit ADCSTRT in CTRL1 by software. When the
conversion is completed, the ADCSTRT bit is cleared by hardware automatically, and the ADCINT bit
in INTVECT is set by hardware at the same time if MADCINT in INTMSK is set.
PWM DACs
Eight 8-bit Static DACs: DAC0−DAC7
• The PWM frequency FPWM = Fosc ÷ 255
• The duty cycle of the PWM output = Register value ÷ 255
• The DC voltage after the low pass filter = VCC × duty cycle
Static DAC application circuit:
Static DAC
Low-pass filter
R
C
VOUTPUT
T = RC
V_OUTPUT = V_CC¡Ñn/255, if T >> T _PWM
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Publication Release Date: December 1999
Revision A1