UM11029
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© NXP Semiconductors N.V. 2017. All rights reserved.
User manual
Rev. 1.0 — 16 June 2017
369 of 515
NXP Semiconductors
UM11029
Chapter 20: LPC84x Standard counter/timer (CTIMER)
20.7.12 PWM Control Register
The PWM Control Register is used to configure the match outputs as PWM outputs. Each
match output can be independently set to perform either as PWM output or as match
output whose function is controlled by the External Match Register (EMR).
A maximum of three single edge controlled PWM outputs can be selected on the
MATn.2:0 outputs. One additional match register determines the PWM cycle length. When
a match occurs in any of the other match registers, the PWM output is set to HIGH. The
timer is reset by the match register that is configured to set the PWM cycle length. When
the timer is reset to zero, all currently HIGH match outputs configured as PWM outputs
are cleared.
7:5
SELCC
Edge select. When bit 4 is 1, these bits select which capture input edge will cause the
timer and prescaler to be cleared. These bits have no effect when bit 4 is low. Note that
different part number and package variations may provide different capture input pin
functions.
0
0x0
Channel 0 Rising Edge. Rising edge of the signal on capture channel 0 clears the timer
(if bit 4 is set).
0x1
Channel 0 Falling Edge. Falling edge of the signal on capture channel 0 clears the timer
(if bit 4 is set).
0x2
Channel 1 Rising Edge. Rising edge of the signal on capture channel 1 clears the timer
(if bit 4 is set).
0x3
Channel 1 Falling Edge. Falling edge of the signal on capture channel 1 clears the timer
(if bit 4 is set).
0x4
Channel 2 Rising Edge. Rising edge of the signal on capture channel 2 clears the timer
(if bit 4 is set).
0x5
Channel 2 Falling Edge. Falling edge of the signal on capture channel 2 clears the timer
(if bit 4 is set).
0x6
Channel 3 Rising Edge. Rising edge of the signal on capture channel 3 clears the timer
(if bit 4 is set).
0x7
Channel 3 Falling Edge. Falling edge of the signal on capture channel 3 clears the timer
(if bit 4 is set).
31:8
-
-
Reserved. Read value is undefined, only zero should be written.
-
Table 381. Count Control Register (CTCR, offset 0x70) bit description
Bit
Symbol
Value
Description
Reset
Value
Table 382. PWM Control Register (PWMC, offset 0x74)) bit description
Bit
Symbol
Value
Description
Reset value
0
PWMEN0
PWM mode enable for channel0.
0
0
Match. CTIMER_MAT0 is controlled by EM0.
1
PWM. PWM mode is enabled for CTIMER_MAT0.
1
PWMEN1
PWM mode enable for channel1.
0
0
Match. CTIMER_MAT01 is controlled by EM1.
1
PWM. PWM mode is enabled for CTIMER_MAT1.
2
PWMEN2
PWM mode enable for channel2.
0
0
Match. CTIMER_MAT2 is controlled by EM2.
1
PWM. PWM mode is enabled for CTIMER_MAT2.