Atmel AT90PWM2 Manual page 131

16.3.1 PSC2 Distinctive Feature
16.3.2 Output Polarity
AT90PWM2/3/2B/3B
132
Figure 16-2. PSC2 versus PSC1&PSC0 Block Diagram
PSC Counter
=
OCRnRB
=
OCRnSB
=
OCRnRA
=
OCRnSA
PICRn
PCNFn
PCTLn
Note: n = 2
PSC2 has two supplementary outputs PSCOUT22 and PSCOUT23. Thanks to a first selector
PSCOUT22 can duplicate PSCOUT20 or PSCOUT21. Thanks to a second selector PSCOUT23
can duplicate PSCOUT20 or PSCOUT21.
The Output Matrix is a kind of 2*2 look up table which gives the possibility to program the output
values according to a PSC sequence
The polarity "active high" or "active low" of the PSC outputs is programmable. All the timing dia-
grams in the following examples are given in the "active high" polarity.
Waveform
Generator B
PSC Input PSCn Input B
Module B
Output
Part A
Matrix
PSCn Input A
PSC Input
Module A
Waveform
Generator A
Part B
PFRCnB POM2(PSC2 only)
PFRCnA PSOCn
(See "Output Matrix" on page
PSCOUTn3
POS23
PSCOUTn1
( From Analog
Comparator n Ouput )
PISELnB
PSCINn
PISELnA
PSCOUTn2
POS22
PSCOUTn0
158.)
4317I–AVR–01/08