Datasheet

133
4317K–AVR–03/2013
AT90PWM2/3/2B/3B
16.3.1 PSC2 Distinctive Feature
Figure 16-2. PSC2 versus PSC1&PSC0 Block Diagram
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 (See “Output Matrix” on page 159.)
16.3.2 Output Polarity
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.
DATABUS
OCRnRB
OCRnSB
OCRnRA
=
=
=
PSC Counter
Waveform
Generator B
PSC Input
Module B
PSC Input
Module A
PSCOUTn1
PCTLn PFRCnA PSOCn
( From Analog
Comparator n Ouput )
OCRnSA
=
PCNFn PFRCnB POM2(PSC2 only)
PICRn
Waveform
Generator A
PSCOUTn0
PSCINn
Part A
Part B
PSCOUTn2
PSCOUTn3
PISELnB
PISELnA
PSCn Input B
PSCn Input A
POS23
POS22
Output
Matrix