UM10503
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User manual
Rev. 1.3 — 6 July 2012
340 of 1269
NXP Semiconductors
UM10503
Chapter 17: LPC43xx GPIO
17.5.1.10 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.
17.5.2 GPIO GROUP0/GROUP1 interrupt register description
17.5.2.1 Grouped interrupt control register
17.5.2.2 GPIO grouped interrupt port polarity registers
The grouped interrupt port polarity registers determine how the polarity of each enabled
pin contributes to the grouped interrupt. Each port n (n = 0 to 7) is associated with its own
port polarity register, and the values of all registers together determine the grouped
interrupt.
Table 195. Pin interrupt status register (IST address 0x4008 7024) 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.
-
-
Table 196. GPIO grouped interrupt control register (CTRL, addresses 0x4008 8000 (GROUP0
INT) and 0x4008 9000 (GROUP1 INT)) bit description
Bit
Symbol
Value
Description
Reset value
0
INT
Group interrupt status. This bit is cleared by writing a
one to it. Writing zero has no effect.
0
0
No interrupt request is pending.
1
Interrupt request is active.
1
COMB
Combine enabled inputs for group interrupt
0
0
OR functionality: A grouped interrupt is generated
when any one of the enabled inputs is active (based
on its programmed polarity).
1
AND functionality: An interrupt is generated when all
enabled bits are active (based on their programmed
polarity).
2
TRIG
Group interrupt trigger
0
0
Edge-triggered
1
Level-triggered
31:3
-
-
Reserved
0