P89LPC932A1 NXP Semiconductors, P89LPC932A1 Datasheet - Page 28

• Manufacturer Part Number: P89LPC932A1
• Description: The P89LPC932A1 is a single-chip microcontroller, available in low cost packages, basedon a high performance processor architecture that executes instructions in two to fourclocks, six times the rate of standard 80C51 devices
• Manufacturer: NXP Semiconductors

NXP Semiconductors
P89LPC932A1_3
Product data sheet
7.19.6 PWM operation
PWM operation has two main modes, symmetrical and asymmetrical.
In asymmetrical PWM operation the CCU Timer operates in down-counting mode
regardless of the direction control bit.
In symmetrical mode, the timer counts up/down alternately. The main difference from
basic timer operation is the operation of the compare module, which in PWM mode is
used for PWM waveform generation.
As with basic timer operation, when the PWM (compare) pins are connected to the
compare logic, their logic state remains unchanged. However, since bit FCO is used to
hold the halt value, only a compare event can change the state of the pin.
Fig 9. Asymmetrical PWM, down-counting
Fig 10. Symmetrical PWM
compare value
compare value
non-inverted
non-inverted
timer value
timer value
inverted
0x0000
inverted
TOR2
TOR2
Rev. 03 — 12 March 2007
0
8-bit microcontroller with accelerated two-clock 80C51 core
P89LPC932A1
002aaa894
002aaa893
© NXP B.V. 2007. All rights reserved.
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