AT90SCR100_09 Datasheet, PDF (147/433 Pages) ATMEL Corporation – 8-bit Microcontroller for Smart Card Readers

AT90SCR100
Table 13-20. Compare Output Mode, non-PWM Mode
COM2B1
COM2B0 Description
0
0
Normal port operation, OC2B disconnected.
0
1
Toggle OC2B on Compare Match
1
0
Clear OC2B on Compare Match
1
1
Set OC2B on Compare Match
Table 13-21 shows the COM2B1:0 bit functionality when the WGM22:0 bits are set to fast PWM
mode.
Table 13-21. Compare Output Mode, Fast PWM Mode⁽¹⁾
COM2B1
COM2B0 Description
0
0
Normal port operation, OC2B disconnected.
0
1
Reserved
1
0
Clear OC2B on Compare Match, set OC2B at BOTTOM
(non-inverting mode)
1
1
Set OC2B on Compare Match, clear OC2B at BOTTOM
(inverting mode)
Note:
1. A special case occurs when OCR2B equals TOP and COM2B1 is set. In this case, the Com-
pare Match is ignored, but the set or clear is done at BOTTOM. See “Fast PWM Mode” on
page 140 for more details.
Table 13-22 shows the COM2B1:0 bit functionality when the WGM22:0 bits are set to phase cor-
rect PWM mode.
Table 13-22. Compare Output Mode, Phase Correct PWM Mode⁽¹⁾
COM2B1
COM2B0 Description
0
0
Normal port operation, OC2B disconnected.
0
1
Reserved
1
0
Clear OC2B on Compare Match when up-counting. Set OC2B on
Compare Match when down-counting.
1
1
Set OC2B on Compare Match when up-counting. Clear OC2B on
Compare Match when down-counting.
Note:
1. A special case occurs when OCR2B equals TOP and COM2B1 is set. In this case, the Com-
pare Match is ignored, but the set or clear is done at TOP. See “Phase Correct PWM Mode” on
page 142 for more details.
• Bits 3..2 – Res: Reserved Bits
These bits are reserved bits in the AT90SCR100 and will always read as zero.
• Bits 1..0 – WGM21..0: Waveform Generation Mode
TPR0327AY–SMS–30Jan09
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