atmega163l ATMEL Corporation, atmega163l Datasheet - Page 55

• Manufacturer Part Number: atmega163l
• Description: Atmega163 8-bit Avr Microcontroller With 16k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

1142E–AVR–02/03
Table 21. Compare Mode Select in PWM Mode
Note that in PWM mode, the value to be written to the Output Compare Register is first
tr an sfe rr ed to a temp o ra ry lo ca tio n , an d the n latc he d in to O CR 2 w h en th e
Timer/Counter reaches $FF. This prevents the occurrence of odd-length PWM pulses
(glitches) in the event of an unsynchronized OCR2 write. See Figure 38 for examples.
Figure 38. Effects of Unsynchronized OCR Latching
CTC2
0
0
0
0
1
1
1
1
COM21
0
0
1
1
0
0
1
1
COM20
0
1
0
1
0
1
0
1
Synchronized OC2 Latch
Unsynchronized OC2 Latch
Effect on Compare Pin
Not connected
Not connected
Cleared on Compare Match, up-counting. Set on
Compare Match, down-counting (non-inverted
PWM).
Cleared on Compare Match, down-counting. Set
on Compare Match, up-counting (inverted PWM).
Not connected
Not connected
Cleared on compare match, set on overflow.
Set on compare match, cleared on overflow.
ATmega163(L)
PWM Output OC2
PWM Output OC2
Frequency
f
f
f
f
TCK0/2
TCK0/2
TCK0/2
TCK0/2
/510
/510
/256
/256
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