NXP Semiconductors LCP43 Series, User Manual

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UM10503 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
User manual Rev. 1.3 — 6 July 2012 888 of 1269
NXP Semiconductors
UM10503
Chapter 30: LPC43xx Motor Control PWM (MOTOCONPWM)
Dead-time counter
When the a channel’s DTE bit is set in CON, the dead-time counter delays the
passive-to-active transitions of both MCO outputs. The dead-time counter starts counting
down, from the channel’s DT value (in the DT register) to 0, whenever the channel’s A or
B output changes from active to passive. The transition of the other output from passive to
active is delayed until the dead-time counter reaches 0. During the dead time, the MCOA
and MCOB output levels are both passive.
Figure 101 shows operation in edge aligned
mode with dead time, and Figure 102 shows center-aligned operation with dead time.
Fig 100. Center-aligned PWM waveform without dead time, POLA = 0
Fig 101. Edge-aligned PWM waveform with dead time, POLA = 0
MAT MAT LIM LIM
0
0
POLA = 0 MCOA
MCOB
active
active
passive passive
passive passive active active
MAT MAT LIM LIM 0
POLA = 0
timer reset timer reset
MCOA
MCOB
active active
passive passive
passive
passive
active active
DT
DT DT
DT