156
AT90PWM216/316 [DATASHEET]
7710H–AVR–07/2013
15.25.9
PSC 1 Configuration Register – PCNF1
15.25.10 PSC 2 Configuration Register – PCNF2
The PSC n Configuration Register is used to configure the running mode of the PSC.
Bit 7 - PFIFTYn: PSC n Fifty
Writing this bit to one, set the PSC in a fifty percent mode where only OCRnRBH/L and OCRnSBH/L are used.
They are duplicated in OCRnRAH/L and OCRnSAH/L during the update of OCRnRBH/L. This feature is useful to
perform fifty percent waveforms.
Bit 6 - PALOCKn: PSC n Autolock
When this bit is set, the Output Compare Registers RA, SA, SB, the Output Matrix POM2 and the PSC Output Con-
figuration PSOCn can be written without disturbing the PSC cycles. The update of the PSC internal registers will be
done at the end of the PSC cycle if the Output Compare Register RB has been the last written.
When set, this bit prevails over LOCK (bit 5)
Bit 5 – PLOCKn: PSC n Lock
When this bit is set, the Output Compare Registers RA, RB, SA, SB, the Output Matrix POM2 and the PSC Output
Configuration PSOCn can be written without disturbing the PSC cycles. The update of the PSC internal registers
will be done if the LOCK bit is released to zero.
Bit 4:3 – PMODEn1: 0: PSC n Mode
Select the mode of PSC.
Bit 2 – POPn: PSC n Output Polarity
If this bit is cleared, the PSC outputs are active Low.
If this bit is set, the PSC outputs are active High.
Bit 1 – PCLKSELn: PSC n Input Clock Select
This bit is used to select between CLKPF or CLKPS clocks.
Set this bit to select the fast clock input (CLKPF).
Bit
7
654
3
2
1
0
PFIFTY1
PALOCK1
PLOCK1
PMODE11
PMODE10
POP1
PCLKSEL1
-
PCNF1
Read/Write
R/W
Initial Value
0
Bit
7
654
3
2
1
0
PFIFTY2
PALOCK2
PLOCK2
PMODE21
PMODE20
POP2
PCLKSEL2
POME2
PCNF2
Read/Write
R/W
Initial Value
0
Table 15-13. PSC n Mode Selection
PMODEn1
PMODEn0
Description
0
One Ramp Mode
01Two Ramp Mode
1
0
Four Ramp Mode
1
Center Aligned Mode