UM11029
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User manual
Rev. 1.0 — 16 June 2017
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NXP Semiconductors
UM11029
Chapter 20: LPC84x Standard counter/timer (CTIMER)
20.7.9 Capture Registers
Each capture register is associated with one capture channel and may be loaded with the
counter/timer value when a specified event occurs on the signal defined for that capture
channel. The signal could originate from an external pin or from an internal source. The
settings in the Capture Control Register register determine whether the capture function is
enabled, and whether a capture event happens on the rising edge of the associated
signal, the falling edge, or on both edges.
20.7.10 External Match Register
The External Match Register provides both control and status of the external match pins.
In the descriptions below, “n” represents the timer number, 0 or 1, and “m” represent a
Match number, 0 through 3.
Match events for Match 0 and Match 1 in the timer can cause a DMA request, see
If the match outputs are configured as PWM output, the function of the external match
register is determined by the PWM rules (
Section 20.8.1 “Rules for single edge controlled
Table 378. Capture Control Register (CCR, offset 0x28) bit description
Bit
Symbol
Description
Reset
Value
0
CAP0RE Rising edge of capture channel 0: a sequence of 0 then 1 causes CR0 to be loaded with the
contents of TC. 0 = disabled. 1 = enabled.
0
1
CAP0FE
Falling edge of capture channel 0: a sequence of 1 then 0 causes CR0 to be loaded with the
contents of TC. 0 = disabled. 1 = enabled.
0
2
CAP0I
Generate interrupt on channel 0 capture event: a CR0 load generates an interrupt.
0
3
CAP1RE Rising edge of capture channel 1: a sequence of 0 then 1 causes CR1 to be loaded with the
contents of TC. 0 = disabled. 1 = enabled.
0
4
CAP1FE
Falling edge of capture channel 1: a sequence of 1 then 0 causes CR1 to be loaded with the
contents of TC. 0 = disabled. 1 = enabled.
0
5
CAP1I
Generate interrupt on channel 1 capture event: a CR1 load generates an interrupt.
0
6
CAP2RE Rising edge of capture channel 2: a sequence of 0 then 1 causes CR2 to be loaded with the
contents of TC. 0 = disabled. 1 = enabled.
0
7
CAP2FE
Falling edge of capture channel 2: a sequence of 1 then 0 causes CR2 to be loaded with the
contents of TC. 0 = disabled. 1 = enabled.
0
8
CAP2I
Generate interrupt on channel 2 capture event: a CR2 load generates an interrupt.
0
9
CAP3RE Rising edge of capture channel 3: a sequence of 0 then 1 causes CR3 to be loaded with the
contents of TC. 0 = disabled. 1 = enabled.
0
10
CAP3FE
Falling edge of capture channel 3: a sequence of 1 then 0 causes CR3 to be loaded with the
contents of TC. 0 = disabled. 1 = enabled.
0
11
CAP3I
Generate interrupt on channel 3 capture event: a CR3 load generates an interrupt.
0
31:12
-
Reserved. Read value is undefined, only zero should be written.
-
Table 379. Capture registers (CR[0:3], offsets [0x2C:0x38]) bit description
Bit
Symbol
Description
Reset value
31:0
CAP
Timer counter capture value.
0