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UM10316_0
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 00.06 — 17 December 2008
242 of 571
1.
How to read this chapter
The contents of this chapter apply to all LPC29xx parts. Available ports depend on the pin
configuration for each part.
2.
GPIO functional description
Each General-Purpose I/O block GPIO provides control over up to 32 port pins. The data
direction (in/out) and output level of each port pin can be programmed individually.
If a port pin is to be used it must first be routed to an I/O pin so that it is available
externally. This part of the configuration is done via the SCU. See
for
information on mapping of GPIO port pins to I/O pins. GPIO port pinning can be found in
A number of points should be noted in regard to SCU mapping of GPIO pins:
•
If an input port is not mapped through the SCU to an external I/O pin it is assigned a
logical 0.
•
If an output port is not mapped through the SCU to an external I/O pin it is left
dangling; i.e. not connected.
The GPIO pins can also be used in an open-drain configuration. In this configuration,
multiple devices can communicate on one signal line in any direction (e.g. bi-directionally).
UM10316
Chapter 16: LPC29xx General Purpose Input/Output (GPIO)
Rev. 00.06 — 17 December 2008
User manual
Table 199. GPIO ports available
Part number
GPIO
port 0
GPIO
port 1
GPIO
port 2
GPIO
port 3
GPIO
port 4
GPIO
port 5
GPIO port 5/
USB
LPC2917/19/01 P0[31:0]
P1[31:0]
P2[27:0] P3[15:0]
-
-
-
LPC2921/23/25 P0[31:0]
P1[27:0]
-
-
-
-
P5[19:18]
LPC2927/29
P0[31:0]
P1[27:0]
P2[27:0] P3[15:0]
-
-
P5[19:18]
LPC2930
P0[31:0]
P1[27:0]
P2[27:0] P3[15:0]
P4[23:0]
P5[15:0]
P5[19:16]
LPC2939
P0[31:0]
P1[27:0]
P2[27:0] P3[15:0]
P4[23:0]
P5[15:0]
P5[19:16]
Fig 60. Schematic representation of the GPIO
GPIO n
GPIO 1
ARM
GPIO 0
I/O pins
(GPIO)
fu
n
c
ti
o
n
s
e
le
ct