131
4317I–AVR–01/08
AT90PWM2/3/2B/3B
16.3
PSC Description
Figure 16-1. Power Stage Controller 0 or 1 Block Diagram
Note:
n = 0, 1
The principle of the PSC is based on the use of a counter (PSC counter). This counter is able to
count up and count down from and to values stored in registers according to the selected run-
ning mode.
The PSC is seen as two symetrical entities. One part named part A which generates the output
PSCOUTn0 and the second one named part B which generates the PSCOUTn1 output.
Each part A or B has its own PSC Input Module to manage selected input.
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 B
Part A
PISELnB
PISELnA
PSCn Input B
PSCn Input A