UM10850
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User manual
Rev. 2.4 — 13 September 2016
126 of 464
NXP Semiconductors
UM10850
Chapter 10: LPC5410x Pin interrupt and pattern match (PINT)
10.6.9 Pin interrupt falling edge register
This register contains ones for pin interrupts selected in the PINTSELn registers (see
) on which a falling edge has been detected. Writing ones to this register clears
falling edge detection. Ones in this register assert an interrupt request for pins that are
enabled for falling-edge interrupts. All edges are detected for all pins selected by the
PINTSELn registers, regardless of whether they are interrupt-enabled.
10.6.10 Pin interrupt status register
Reading this register returns ones for pin interrupts that are currently requesting an
interrupt. For pins identified as edge-sensitive in the Interrupt Select register, writing ones
to this register clears both rising- and falling-edge detection for the pin. For level-sensitive
pins, writing ones inverts the corresponding bit in the Active level register, thus switching
the active level on the pin.
10.6.11 Pattern Match Interrupt Control Register
The pattern match control register contains one bit to select pattern-match interrupt
generation (as opposed to pin interrupts which share the same interrupt request lines),
and another to enable the RXEV output to the CPU. This register also allows the current
state of any pattern matches to be read.
If the pattern match feature is not used (either for interrupt generation or for RXEV
assertion) bits SEL_PMATCH and ENA_RXEV of this register should be left at 0 to
conserve power.
Remark:
Set up the pattern-match configuration in the PMSRC and PMCFG registers
before writing to this register to enable (or re-enable) the pattern-match functionality. This
eliminates the possibility of spurious interrupts as the feature is being enabled.
Table 165. Pin interrupt falling edge register (FALL, address 0x4001 8020) bit description
Bit
Symbol
Description
Reset value Access
7:0
FDET
Falling edge detect. Bit n detects the falling edge of the pin selected in PINTSELn.
Read 0: No falling edge has been detected on this pin since Reset or the last time
a one was written to this bit.
Write 0: no operation.
Read 1: a falling edge has been detected since Reset or the last time a one was
written to this bit.
Write 1: clear falling edge detection for this pin.
0
R/W
31:8 -
Reserved.
-
-
Table 166. Pin interrupt status register (IST, address 0x4001 8024) bit description
Bit
Symbol
Description
Reset value Access
7:0
PSTAT
Pin interrupt status. Bit n returns the status, clears the edge interrupt, or inverts the
active level of the pin selected in PINTSELn.
Read 0: interrupt is not being requested for this interrupt pin.
Write 0: no operation.
Read 1: interrupt is being requested for this interrupt pin.
Write 1 (edge-sensitive): clear rising- and falling-edge detection for this pin.
Write 1 (level-sensitive): switch the active level for this pin (in the IENF register).
0
R/W
31:8 -
Reserved.
-
-