LM3S1651 Datasheet, PDF (813/1033 Pages) Texas Instruments – ARM and Thumb are registered trademarks and Cortex is a trademark

Stellaris^® LM3S1651 Microcontroller
Figure 18-3 on page 813 shows the behavior of the counter and the relationship of these pulses
when the counter is in Count-Down mode. Figure 18-4 on page 814 shows the behavior of the counter
and the relationship of these pulses when the counter is in Count-Up/Down mode. In these figures,
the following definitions apply:
■ LOAD is the value in the PWMnLOAD register
■ COMPA is the value in the PWMnCMPA register
■ COMPB is the value in the PWMnCMPB register
■ 0 is the value zero
■ load is the internal signal that has a single-clock-cycle-width High pulse when the counter is
equal to the load value
■ zero is the internal signal that has a single-clock-cycle-width High pulse when the counter is zero
■ cmpA is the internal signal that has a single-clock-cycle-width High pulse when the counter is
equal to COMPA
■ cmpB is the internal signal that has a single-clock-cycle-width High pulse when the counter is
equal to COMPB
■ dir is the internal signal that indicates the count direction
Figure 18-3. PWM Count-Down Mode
LOAD
COMPA
COMPB
0
load
zero
cmpA
cmpB
dir
BDown
ADown
January 21, 2012
813
Texas Instruments-Production Data