lpc2917 NXP Semiconductors, lpc2917 Datasheet - Page 29

• Manufacturer Part Number: lpc2917
• Description: Arm9 Microcontroller With Can And Lin
• Manufacturer: NXP Semiconductors

NXP Semiconductors
LPC2917_19_1
Preliminary data sheet
8.4.6.1 Overview
8.4.6.2 Description
8.4.6.3 GPIO pin description
8.4.6.4 GPIO clock description
8.4.6 General-purpose I/O
The LPC2917/19 contains four general-purpose I/O ports located at different peripheral
base addresses. In the 144-pin package all four ports are available. All I/O pins are
bi-directional, and the direction can be programmed individually. The I/O pad behavior
depends on the configuration programmed in the port function-select registers.
The key features are:
The general-purpose I/O provides individual control over each bi-directional port pin.
There are two registers to control I/O direction and output level. The inputs are
synchronized to achieve stable read-levels.
To generate an open-drain output, set the bit in the output register to the desired value.
Use the direction register to control the signal. When set to output, the output driver
actively drives the value on the output: when set to input the signal floats and can be
pulled up internally or externally.
The five GPIO ports in the LPC2917/19 have the pins listed below. The GPIO pins are
combined with other functions on the port pins of the LPC2917/19.
GPIO pins.
Table 17.
The GPIO modules are clocked by several clocks, all of which are derived from
BASE_SYS_CLK; CLK_SYS_PESS and CLK_SYS_GPIOx (x = 0-3), see
Note that each GPIO has its own CLK__SYS_GPIOx branch clock for power
management. The frequency of all clocks CLK_SYS_GPIOx is identical to
CLK_SYS_PESS since they are derived from the same base clock BASE_SYS_CLK.
Symbol
GPIO0 pin[31:0]
GPIO1 pin[31:0]
GPIO2 pin[27:0]
GPIO3 pin[15:0]
•
•
•
•
General-purpose parallel inputs and outputs
Direction control of individual bits
Synchronized input sampling for stable input-data values
All I/O defaults to input at reset to avoid any possible bus conflicts
GPIO pins
Direction
in/out
in/out
in/out
in/out
Rev. 1.01 — 15 November 2007
Description
GPIO port x pins 31 to 0
GPIO port x pins 31 to 0
GPIO port x pins 27 to 0
GPIO port x pins 15 to 0
ARM9 microcontroller with CAN and LIN
LPC2917/19
Table 17
© NXP B.V. 2007. All rights reserved.
Section
shows the
7.2.2.
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