UM10429
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© NXP B.V. 2010. All rights reserved.
User manual
Rev. 1 — 20 October 2010
68 of 258
NXP Semiconductors
UM10429
Chapter 9: LPC1102 General Purpose I/O (GPIO)
Read operation
If the address bit associated with the GPIO data bit is HIGH, the value is read. If the
address bit is LOW, the GPIO data bit is read as 0. Reading a port DATA register yields
the state of port pins 11:0 ANDed with address bits 13:2.
Fig 9.
Masked read operation
0
0
0
0
0
0
1
1
0
0
0
1
1
1
1
1
1
1
1
0
0
1
0
0
0
0
0
0
0
0
1
0
0
0
0
0
13
12
11
10
9
8
7
6
5
4
3
2
0
0
ADDRESS[13:2]
address 0x0C4
port pin settings
data read