Rainbow Electronics ATtiny26L - Manual (Page 56)

56
ATtiny26(L)
1477B–AVR–04/02
In PWM mode, the Timer Overflow Flag – TOV1, is set as in normal Timer/Counter
mode. Timer Overflow Interrupt1 operates exactly as in normal Timer/Counter mode,
i.e., it is executed when TOV1 is set provided that Timer Overflow Interrupt and global
interrupts are enabled. This also applies to the Timer Output Compare flags and
interrupts.
The frequency of the PWM will be Timer Clock 1 Frequency divided by (OCR1C
value + 1). See the following equation:
Resolution shows how many bit is required to express the value in the OCR1C Register.
It is calculated by following equation
Resolution
PWM
= log
2
(OCR1C + 1)
Table 26. PWM Outputs OCR1x = $00 or OCR1C, x = A or B
COM1x1 COM1x0 OCR1x Output OC1x Output OC1x
0 1 $00 L H
0 1 OCR1C H L
1 0 $00 L Not connected
1 0 OCR1C H Not connected
1 1 $00 H Not connected
1 1 OCR1C L Not connected
f
PWM
f
TCK1
OCR1C + 1 ( )
------------------------------------ =