
161
4378C–AVR–09/08
AT90PWM1
Bit 1 – PCCYC2 : PSC 2 Complete Cycle
When this bit is set, the PSC 2 completes the entire waveform cycle before halt operation
requested by clearing PRUN2. This bit is not relevant in slave mode (PARUN2 = 1).
Bit 0 – PRUN2 : PSC 2 Run
Writing this bit to one starts the PSC 2.
When set, this bit prevails over PARUN2 bit.
16.25.13 PSC n Input A Control Register – PFRCnA
16.25.14 PSC n Input B Control Register – PFRCnB
The Input Control Registers are used to configure the 2 PSC’s Retrigger/Fault block A & B. The
2 blocks are identical, so they are configured on the same way.
Bit 7 – PCAEnx : PSC n Capture Enable Input Part x
Writing this bit to one enables the capture function when external event occurs on input selected
as input for Part x (see PISELnx bit in the same register).
Bit 6 – PISELnx : PSC n Input Select for Part x
Clear this bit to select PSCINn as input of Fault/Retrigger block x.
Set this bit to select Comparator n Output as input of Fault/Retrigger block x.
Bit 5 –PELEVnx : PSC n Edge Level Selector of Input Part x
When this bit is clear, the falling edge or low level of selected input generates the significative
event for retrigger or fault function .
When this bit is set, the rising edge or high level of selected input generates the significative
event for retrigger or fault function.
Bit 4 – PFLTEnx : PSC n Filter Enable on Input Part x
Setting this bit (to one) activates the Input Capture Noise Canceler. When the noise canceler is
activated, the input from the retrigger pin is filtered. The filter function requires four successive
equal valued samples of the retrigger pin for changing its output. The Input Capture is therefore
delayed by four oscillator cycles when the noise canceler is enabled.
Bit
7
6543
2
1
0
PCAEnA
PISELnA
PELEVnA
PFLTEnA
PRFMnA3
PRFMnA2
PRFMnA1
PRFMnA0
PFRCnA
Read/Write
R/W
Initial Value
0
0000
0
Bit
7
6543
2
1
0
PCAEnB
PISELnB
PELEVnB
PFLTEnB
PRFMnB3
PRFMnB2
PRFMnB1
PRFMnB0
PFRCnB
Read/Write
R/W
Initial Value
0
0000
0