at90pwm81-16se ATMEL Corporation, at90pwm81-16se Datasheet - Page 105

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

13.5.2
13.5.2.1
13.5.2.2
7734M–AVR–03/10
Running Mode Description
Four Ramp Mode
Two Ramp Mode
Waveforms and length of output signals are determined by Time Parameters (DT0, OT0, DT1, OT1) and
by the running mode. Four modes are possible :
In Four Ramp mode, each time in a cycle has its own definition
Figure 13-6.
The input clock of PSC is given by CLKPSC.
PSCOUTn0 and PSCOUTn1 signals are defined by On-Time 0, Dead-Time 0, On-Time 1 and Dead-Time
1 values with :
On-Time 0 = OCRnRAH/L * 1/Fclkpsc
On-Time 1 = OCRnRBH/L * 1/Fclkpsc
Dead-Time 0 = (OCRnSAH/L + 2) * 1/Fclkpsc
Dead-Time 1 = (OCRnSBH/L + 2) * 1/Fclkpsc
Note:
In Two Ramp mode, the whole cycle is divided in two moments
One moment for PSCn0 description with OT0 which gives the time of the whole moment
One moment for PSCn1 description with OT1 which gives the time of the whole moment
PSC Counter
PSCOUTn0
PSCOUTn1
– Four Ramp mode
– Two Ramp mode
– One Ramp mode
– Center Aligned mode
Minimal value for Dead-Time 0 and Dead-Time 1 = 2 * 1/Fclkpsc
OCRnSA
0
PSCn0 & PSCn1 Basic Waveforms in Four Ramp mode
Dead-Time 0
On-Time 0
PSC Cycle
OCRnRA
0
OCRnSB
Dead-Time 1
On-Time 1
OCRnRB
AT90PWM81
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