Philips LPC2101 - Chapter 7: Pin Connect Block; Applications; Description; Features

© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
User manual Rev. 01 — 12 January 2006 66
7.1 Features
The Pin connect block allows individual pin configuration.
7.2 Applications
The purpose of the pin connect block is to configure the microcontroller pins to the desired
functions.
7.3 Description
The pin connect block allows selected pins of the microcontroller to have more than one
function. Configuration registers control the multiplexers to allow connection between the
pin and the on chip peripherals.
Peripherals should be connected to the appropriate pins prior to being activated, and prior
to any related interrupt(s) being enabled. Activity of any enabled peripheral function that is
not mapped to a related pin should be considered undefined.
Selection of a single function on a port pin completely excludes all other functions
otherwise available on the same pin.
The only partial exception from the above rule of exclusion is the case of inputs to the A/D
converter. Regardless of the function that is currently selected for the port pin hosting the
A/D input, this A/D input can be read at any time and variations of the voltage level on this
pin will be reflected in the A/D readings. However, valid analog reading(s) can be obtained
if and only if the function of an analog input is selected. Only in this case the proper
interface circuit is active between the physical pin and the A/D module. In all other cases,
a part of digital logic necessary for the digital function to be performed will be active and
will disrupt proper behavior of the A/D.
7.4 Register description
The Pin Control Module contains 2 registers as shown in Ta ble 5 9 below.
[1] Reset value reflects the data stored in used bits only. It does not include reserved bits content.
UM10161
Chapter 7: Pin connect block
Rev. 01 — 12 January 2006 User manual
Table 59: Pin connect block register map
Name Description Access Reset value
[1]
Address
PINSEL0 Pin function select
register 0.
Read/Write 0x0000 0000 0xE002 C000
PINSEL1 Pin function select
register 1.
Read/Write 0x0000 0000 0xE002 C004