UM10850
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2016. All rights reserved.
User manual
Rev. 2.4 — 13 September 2016
135 of 464
NXP Semiconductors
UM10850
Chapter 10: LPC5410x Pin interrupt and pattern match (PINT)
10.7 Functional description
10.7.1 Pin interrupts
In this interrupt facility, up to 8 pins are identified as interrupt sources by the Pin Interrupt
Select registers (PINTSEL0-7). All registers in the pin interrupt block contain 8 bits,
corresponding to the pins called out by the PINTSEL0-7 registers. The ISEL register
defines whether each interrupt pin is edge- or level-sensitive. The RISE and FALL
registers detect edges on each interrupt pin, and can be written to clear (and set) edge
detection. The IST register indicates whether each interrupt pin is currently requesting an
interrupt, and this register can also be written to clear interrupts.
The other pin interrupt registers play different roles for edge-sensitive and level-sensitive
pins, as described in
10.7.2 Pattern Match engine example
Suppose the desired boolean pattern to be matched is:
(IN1) + (IN1 * IN2) + (~IN2 * ~IN3 * IN6fe) + (IN5 * IN7ev)
with:
IN6fe = (sticky) falling-edge on input 6
IN7ev = (non-sticky) event (rising or falling edge) on input 7
Each individual term in the expression shown above is controlled by one bit-slice. To
specify this expression, program the pattern match bit slice source and configuration
register fields as follows:
•
PMSRC register (
):
–
Since bit slice 5 will be used to detect a sticky event on input 6, a 1 can be written
to the SRC5 bits to clear any pre-existing edge detects on bit slice 5.
–
SRC0: 001 - select input 1 for bit slice 0
–
SRC1: 001 - select input 1 for bit slice 1
–
SRC2: 010 - select input 2 for bit slice 2
–
SRC3: 010 - select input 2 for bit slice 3
–
SRC4: 011 - select input 3 for bit slice 4
–
SRC5: 110 - select input 6 for bit slice 5
–
SRC6: 101 - select input 5 for bit slice 6
Table 170. Pin interrupt registers for edge- and level-sensitive pins
Name
Edge-sensitive function
Level-sensitive function
IENR
Enables rising-edge interrupts.
Enables level interrupts.
SIENR
Write to enable rising-edge interrupts.
Write to enable level interrupts.
CIENR
Write to disable rising-edge interrupts.
Write to disable level interrupts.
IENF
Enables falling-edge interrupts.
Selects active level.
SIENF
Write to enable falling-edge interrupts.
Write to select high-active.
CIENF
Write to disable falling-edge interrupts.
Write to select low-active.