20-668-0024 Rabbit Semiconductor, 20-668-0024 Datasheet - Page 253

• Manufacturer Part Number: 20-668-0024
• Description: IC CPU RABBIT4000 128-LQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 20-668-0024

• Processor Type: Rabbit 4000 8-bit
• Speed: 60MHz
• Voltage: 2.5V, 2.7V, 3V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 128-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Other names: 20-668-0022; 316-1078

23.3 Operation
The following steps explain how to set up a PWM channel.
1. Configure Timer A9 via TAT9R to provide the desired PWM clock frequency.
2. Configure PWLxR to select whether to spread the PWM output throughout the cycle.
3. Configure PWLxR to select whether to suppress the PWM output.
4. Configure the duty cycle by writing to PWLxR and PWMxR.
23.3.1 Handling Interrupts
The following steps explain how an interrupt is set up and used.
1. Write the vector to the interrupt service routine to the internal interrupt table.
2. Configure PWL0R to select the PWM interrupt priority and PWL1R to select PWM
The following actions occur within the interrupt service routine.
• Any PWM values may be updated.
• The interrupt request should be cleared by writing to any PWM register.
23.3.2 Example ISR
A sample interrupt handler is shown below.
Chapter 23 Pulse Width Modulator
interrupt suppression (if an interrupt is desired).
pwm_isr::
push af
ld a, 0x55
ioi ld (PWM0R), a
; note that interrupt request is also cleared by register write above
pop af
ipres
ret
; save used registers
; restore used registers
; update a PWM value
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