
UM10800
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User manual
Rev. 1.2 — 5 October 2016
127 of 487
NXP Semiconductors
UM10800
Chapter 9: LPC82x General Purpose I/O (GPIO)
9.5.6 GPIO masked port pin registers
These registers are similar to the PORT registers, except that the value read is masked by
ANDing with the inverted contents of the corresponding MASK register, and writing to one
of these registers only affects output register bits that are enabled by zeros in the
corresponding MASK register
9.5.7 GPIO port set registers
Output bits can be set by writing ones to these registers, regardless of MASK registers.
Reading from these register returns the port’s output bits, regardless of pin directions.
9.5.8 GPIO port clear registers
Output bits can be cleared by writing ones to these write-only registers, regardless of
MASK registers.
Table 118. GPIO port pin register (PIN0, address 0xA000 2100) bit description
Bit
Symbol Description
Reset
value
Access
28:0
PORT
Reads pin states or loads output bits (bit 0 = PIO0_0, bit 1 =
PIO0_1, ..., bit 38 = PIO0_28).
0 = Read: pin is low; write: clear output bit.
1 = Read: pin is high; write: set output bit.
ext
R/W
31:29
-
Reserved.
0
-
Table 119. GPIO masked port pin register (MPIN0, address 0xA000 2180) bit description
Bit
Symbol
Description
Reset
value
Access
28:0
MPORTP
Masked port register (bit 0 = PIO0_0, bit 1 =PIO0_1, ..., bit
28 = PIO0_28).
0 = Read: pin is LOW and/or the corresponding bit in the
MASK register is 1; write: clear output bit if the
corresponding bit in the MASK register is 0.
1 = Read: pin is HIGH and the corresponding bit in the
MASK register is 0; write: set output bit if the
corresponding bit in the MASK register is 0.
ext
R/W
31:29
-
Reserved.
0
-
Table 120. GPIO port set register (SET0, address 0xA000 2200) bit description
Bit
Symbol
Description
Reset
value
Access
28:0
SETP
Read or set output bits (bit 0 = PIO0_0, bit 1 =PIO0_1, ...,
bit 28 = PIO0_28).
0 = Read: output bit: write: no operation.
1 = Read: output bit; write: set output bit.
0
R/W
31:29
-
Reserved.
0
-