at90pwm81-16se ATMEL Corporation, at90pwm81-16se Datasheet - Page 151

• Manufacturer Part Number: at90pwm81-16se
• Description: 8-bit Avr Microcontroller With 8k Bytes In- System Programmable Flash
• Manufacturer: ATMEL Corporation

14.5
14.5.1
14.5.2
7734M–AVR–03/10
Functional Description
Waveform Cycles
Running Mode Description
The waveform generated by PSCR can be described as a sequence of two waveforms.
The first waveform is relative to PSCOUTr0 output and part A of PSC. The part of this waveform is sub-
cycle A in the following figure.
The second waveform is relative to PSCOUTr1 output and part B of PSC. The part of this waveform is
sub-cycle B in the following figure.
The complete waveform is ended with the end of sub-cycle B. It means at the end of waveform B.
Figure 14-3.
Ramps illustrate the output of the PSCR counter included in the waveform generators. Centered Mode is
like a one ramp mode which count down up and down.
Notice that the update of a new set of values is done regardless of ramp Mode at the top of the last ramp.
Waveforms and length of output signals are determined by Time Parameters (DT0, OT0, DT1, OT1) and
by the running mode. Three modes are possible :
The active time of PSCOUTn0 is given by the OT0 value. The active time of PSCOUTn1 is given by the
OT1 value. Both of them are 12 bit values. Thanks to DT0 & DT1 to adjust the dead time between
PSCOUTn0 and PSCOUTn1 active signals.
4 Ramp Mode
2 Ramp Mode
1 Ramp Mode
– Four Ramp mode
– Two Ramp mode
– One Ramp mode
Ramp A0
Cycle Presentation in 1, 2 & 4 Ramp Mode
Sub-Cycle A
Ramp A
Ramp A1
PSC Cycle
Ramp B0
Sub-Cycle B
Ramp B
Ramp B1
UPDATE
AT90PWM81
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