NXP Semiconductors LPC24XX UM10237 - Manual (Page 178)

UM10237_4 © NXP B.V. 2009. All rights reserved.
User manual Rev. 04 — 26 August 2009 178 of 792
NXP Semiconductors
UM10237
Chapter 9: LPC24XX Pin connect
3. Pin function select register values
The PINSEL registers control the functions of device pins as shown below. Pairs of bits in
these registers correspond to specific device pins.
The direction control bit in the GPIO registers is effective only when the GPIO function is
selected for a pin. For other functions, direction is controlled automatically. Each
derivative typically has a different pinout and therefore a different set of functions possible
for each pin. Details for a specific derivative may be found in the appropriate data sheet.
4. Pin mode select register values
The PINMODE registers control the on-chip pull-up/pull-down resistor feature for all GPIO
ports. Two bits are used to control a port pin. PINMODEn register bits are reserved for not
available pins, e.g. pins P2[15:14] are not available on LPC2458 and are reserved in
PINSEL5 and PINMODE5.
5. Register description
The Pin Control Module contains 12 registers as shown in Table 9–129 below.
Remark: The LCD pins in the PINSEL registers are available on the LPC247x only.
Table 127. Pin function select register bits
PINSEL0 to
PINSEL9 Values Function Value after Reset
00 Primary (default) function, typically GPIO port 00
01 First alternate function
10 Second alternate function
11 Third alternate function
Table 128. Pin Mode Select register bits
PINMODE0 to
PINMODE9
Values Function Value after Reset
00 Pin has an on-chip pull-up resistor enabled. 00
01 Reserved. This value should not be used.
10 Pin has neither pull-up nor pull-down resistor enabled.
11 Pin has an on-chip pull-down resistor enabled.
Table 129. Summary of pin connect block registers
Name Description Access Reset Value [1] Address
PINSEL0 Pin function select register 0 R/W 0x0000 0000 0xE002 C000
PINSEL1 Pin function select register 1 R/W 0x0000 0000 0xE002 C004
PINSEL2 Pin function select register 2 R/W 0x0000 0000 0xE002 C008
PINSEL3 Pin function select register 3 R/W 0x0000 0000 0xE002 C00C
PINSEL4 Pin function select register 4 R/W 0x0000 0000 0xE002 C010
PINSEL5 Pin function select register 5 R/W 0x0000 0000 0xE002 C014