z8f1601 ZiLOG Semiconductor, z8f1601 Datasheet - Page 80

• Manufacturer Part Number: z8f1601
• Description: Z8 Encore!? Microcontroller With Flash Memory And 10-bit A/d Converter
• Manufacturer: ZiLOG Semiconductor

PS017609-0803
PWM Output High Time Ratio (%)
2. Write to the Timer High and Low Byte registers to set the starting count value
3. Write to the PWM High and Low Byte registers to set the PWM value.
4. Write to the Timer Reload High and Low Byte registers to set the Reload value (PWM
5. If desired, enable the timer interrupt and set the timer interrupt priority by writing to
6. Configure the associated GPIO port pin for the Timer Output alternate function.
7. Write to the Timer Control register to enable the timer and initiate counting.
The PWM period is given by the following equation:
If an initial starting value other than
registers, the One-Shot mode equation must be used to determine the first PWM time-out
period.
If TPOL is set to 0, the ratio of the PWM output High time to the total period is given by:
If TPOL is set to 1, the ratio of the PWM output High time to the total period is given by:
PWM Output High Time Ratio (%)
Capture Mode
In Capture mode, the current timer count value is recorded when the desired external
Timer Input transition occurs. The Capture count value is written to the Timer PWM High
and Low Byte Registers. The timer input is the system clock. The TPOL bit in the Timer
Control register determines if the Capture occurs on a rising edge or a falling edge of the
PWM Period (s)
–
–
–
–
(typically
reset in PWM mode, counting always begins at the reset value of
period). The Reload value must be greater than the PWM value.
the relevant interrupt registers.
Disable the timer
Configure the timer for PWM mode.
Set the prescale value.
Set the initial logic level (High or Low) and PWM High/Low transition for the
Timer Output alternate function.
0001H
=
). This only affects the first pass in PWM mode. After the first timer
--------------------------------------------------------------------------- -
System Clock Frequency (Hz)
Reload Value Prescale
0001H
Z8F640x/Z8F480x/Z8F320x/Z8F240x/Z8F160x
=
=
´
Reload Value PWM Value
----------------------------------------------------------------------- -
--------------------------------- -
Reload Value
PWM Value
is loaded into the Timer High and Low Byte
Reload Value
–
´
100
0001H
´
100
Z8 Encore!
.
Timers
®
62