SAB80515 Datasheet, PDF (91/270 Pages) Siemens Semiconductor Group – 8-Bit Single-Chip Microcontroller Family

On-Chip Peripheral Components
Figure 7-38
Modulation Range of a PWM Signal, Generated with a
Timer 2/CCx Register Combination in Compare Mode 0
The following example shows how to calculate the modulation range for a PWM signal. To calculate
with reasonable numbers, a reduction of the resolution to 8-bit is used. Otherwise (for the maximum
resolution of 16-bit) the modulation range would be so severely limited that it would be negligible.
Example:
Timer 2 in auto-reload mode; contents of reload register CRC = 0FF00H
Restriction of modulation range =
1
x 100% = 0.195%
256 x 2
This leads to a variation of the duty cycle from 0.195% to 99.805% for a timer 2/CCx register
configuration when 8 of 16 bits are used.
Semiconductor Group
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