UM10237_2 © NXP B.V. 2008. All rights reserved.
User manual Rev. 02 — 19 December 2008 198 o f 792
NXP Semiconductors UM10237
Chapter 10: LPC24XX General Purpose Input/Output (GPIO)
[1] Reset value reflects the data stored in used bits only. It does not include reserved bits content.
6.1 GPIO port Direction register IODIR and FIODIR(IO[0/1]DIR - 0xE002 80[0/1]8 and FIO[0/1/2/3/4]DIR - 0x3FFF C0[0/2/4/6/8]0)

This word accessible register is used to control the direction of the pins when they are

configured as GPIO port pins. Direction bit for any pin must be set according to the pin

functionality.

Remark: GPIO pins P0.29 and P0.30 are shared with the USB D+/ pins and must have

the same direction. If either P0DIR bits 29 or 30 are configured LOW in the IO0DIR or

FIO0DIR registers, both, P0.29 and P0.30, are inputs. If both, P0DIR bit 29 and bit 30 are

HIGH, both, P0.29 and P0.30, are outputs.

Legacy registers are the IO0DIR and IO1DIR while the enhanced GPIO functions are

supported via the FIO0DIR, FIO1DIR, FIO2DIR, FIO3DIR and FIO4DIR registers.

Table 160. GPIO interru pt reg i ster map
Generic
Name Description Access Reset
value[1] PORTn Register
Address & Name
IntEnR GPIO In terrupt Enable for Rising edge. R/W 0x0 IO0IntEnR - 0xE002 8090
IO2IntEnR - 0xE002 80B0
IntEnF GPIO Interrupt Enable for Falling edge. R/W 0x0 IO0IntEnR - 0xE0028094
IO2IntEnR - 0xE002 80B4
IntStatR GPIO Interrupt Status for Rising edge. RO 0x0 IO0IntStatR - 0xE0028084
IO2IntStatR - 0xE00280A4
IntStatF GPIO Interrupt Status for Falling edge. RO 0x0 IO0IntStatF - 0xE0028088
IO2IntStatF - 0xE00280A8
IntClr GPIO Interrupt Clear. WO 0x0 IO0IntClr - 0xE002808C
IO2IntClr - 0xE002 80AC
IntStatus GPIO overall Interrupt Status. RO 0x00 IOIntStatus - 0xE002 8080
Table 161. GPIO port Direction register (IO0DIR - address 0xE002 8008 and IO1DIR - address
0xE002 8018) bit description
Bit Symbol Value Description Reset
value
31:0 P0xDIR
or
P1xDIR 0
Slow GPIO Direction PORTx control bits. Bit 0 in IOxDIR
controls pin Px.0, bit 31 IOxDIR controls pin Px.31.
Controlled pin is an input pin.
0x0
1 Controlled pin is an output pin.
Table 162. Fast GPIO port Dir ection register (FIO[0/1/2/3/4]DIR - address
0x3FFF C0[0/2/4/6/8]0) bit description
Bit Symbol Value Description Reset
value
31:0 FP0xDIR
FP1xDIR
FP2xDIR
FP3xDIR
FP4xDIR
0
Fast GPIO Direction PORTx control bits. Bit 0 in FIOxDIR
controls pin Px.0, bit 31 in FIOxDIR controls pin Px.31.
Controlled pin is input.
0x0
1 Controlled pin is output.