Datasheet

LPC2104_2105_2106_7 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 07 — 20 June 2008 16 of 41
NXP Semiconductors
LPC2104/2105/2106
Single-chip 32-bit microcontrollers
6.9 General purpose parallel I/O
Device pins that are not connected to a specific peripheral function are controlled by the
GPIO registers. Pins may be dynamically configured as inputs or outputs. Separate
registers allow setting or clearing any number of outputs simultaneously. The value of the
output register may be read back, as well as the current state of the port pins.
6.9.1 Features
• Direction control of individual bits.
• Separate control of output set and clear.
• All I/O default to inputs after reset.
6.9.2 Features added with the Fast GPIO set of registers available on
LPC2104/2105/2106/01 only
• Fast GPIO registers are relocated to the ARM local bus for the fastest possible I/O
timing, enabling port pin toggling up to 3.5 times faster than earlier LPC2000 devices.
• Mask registers allow treating sets of port bits as a group, leaving other bits
unchanged.
• All Fast GPIO registers are byte addressable.
• Entire port value can be written in one instruction.
• Ports are accessible via either the legacy group of registers (GPIOs) or the group of
registers providing accelerated port access (Fast GPIOs).
6.10 UARTs
The LPC2104/2105/2106 each contain two UARTs. One UART provides a full modem
control handshake interface, the other provides only transmit and receive data lines.
6.10.1 Features
• 16 byte Receive and Transmit FIFOs
• Register locations conform to 16C550 industry standard
• Receiver FIFO trigger points at 1 B, 4 B, 8 B, and 14 B
• Built-in baud rate generator
25:24 P0.28 0 0 GPIO Port 0.28 0
0 1 TMS
27:26 P0.29 0 0 GPIO Port 0.29 0
0 1 TCK
29:28 P0.30 0 0 GPIO Port 0.30 0
0 1 TDI
31:30 P0.31 0 0 GPIO Port 0.31 0
0 1 TDO
Table 7. Pin function select register 1 (PINSEL1 - 0xE002 C004)
…continued
PINSEL1 Pin name Value Function Value after
reset