Datasheet

105
7734Q–AVR–02/12
AT90PWM81/161
Figure 12-4. Cycle presentation in 1, 2, and 4 ramp mode.
Figure 12-5. Cycle presentation in centered mode.
Ramps illustrate the output of the PSC 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.
12.5.2 Running Mode Description
Waveforms and length of output signals are determined by Time Parameters (DT0, OT0, DT1,
OT1) and by the running mode. Four modes are possible:
– Four Ramp mode
–Two Ramp mode
–One Ramp mode
– Center Aligned mode
12.5.2.1 Four Ramp Mode
In Four Ramp mode, each time in a cycle has its own definition.
4 Ramp Mode
2 Ramp Mode
1 Ramp Mode
Sub-Cycle ASub-Cycle B
PSC Cycle
UPDATE
Ramp A0 Ramp A1 Ramp B0 Ramp B1
Ramp A Ramp B
PSC Cycle
UPDATE
Centered Mode