![NXP Semiconductors LPC29 Series Скачать руководство пользователя страница 430](http://html1.mh-extra.com/html/nxp-semiconductors/lpc29-series/lpc29-series_user-manual_1721826430.webp)
DR
AFT
DR
AFT
DRAFT
DR
D
RAFT
DRAFT
DRA
FT DRAF
D
RAFT DRAFT DRAFT DRAFT DRAFT D
DRAFT
D
RAFT DRA
FT DRAFT DRAFT DRAFT DRA
UM10316_0
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 00.06 — 17 December 2008
430 of 571
NXP Semiconductors
UM10316
Chapter 25: LPC29xx Pulse Width Modulator (PWM)
4.1 PWM counter synchronization
Several PWMs can be synchronized using TRANS_ENABLE_IN and
TRANS_ENABLE_OUT (see
) and the SYNC_IN and SYNC_OUT ports.
A PWM module can also provide synchronization signals to other modules. The signal
SYNC_OUT is a pulse of one clock cycle’s duration generated when the internal PWM
counter starts or restarts. The signal TRANS_ENABLE_OUT is a pulse synchronous with
SYNC_OUT, but generated if a shadow register update occurs when the PWM counter
restarts. By using the SYNDEL register a delay can be inserted between the counter start
and the generation of TRANS_ENABLE_OUT and SYNC_OUT.
4.2 Delayed register update triggered by timer 0
The update of the PWM configuration registers (CTRL, PRD, PRSC, SYNDEL, CNT,
MTCHACT, MTCHDEACT) can also be triggered by hardware. This is done through the
trans_enable_in signal of each PWM block. The match3 output of the MSCSS Timer0
(Timer_ADC) can be used to trigger the register update.
Fig 111.PWM operation
t
16-bit
internal
counter
PWM0
t
PWM0
output
MTCHACT
MTCHDEACT
Sync_in_0
Sync_out_0
Global programmable sync_delay
PRD
PWM1
output
Sync_in_1
==
Sync_out_0
Sync_out_1
t