DRAFT
DRAFT DRAFT DR
DRAFT DRAFT DRAFT
D
RAF
DRAFT DRAFT DRA
FT D
RAFT DR
AFT D
DRA
FT DRAFT DRAFT
D
RAFT
DRAFT
D
RAFT
DRA
UM10601
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2012. All rights reserved.
Preliminary user manual
Rev. 1.0 — 7 November 2012
156 of 313
NXP Semiconductors
UM10601
Chapter 13: LPC800 Analog comparator
13.4 Pin description
The analog comparator reference voltage, the inputs, and the output are assigned to
external pins through the switch matrix. You can assign the analog comparator output to
any pin on the package that is not a supply or ground pin. The comparator inputs and the
reference voltage are fixed-pin functions that must be enabled through the switch matrix
and can only be assigned to special pins on the package.
See
Section 9.3.1 “Connect an internal signal to a package pin”
to assign the analog
comparator output to any pin on the LPC800 package.
to enable the analog comparator inputs and the reference voltage input.
13.5 General description
The analog comparator can compare voltage levels on external pins and internal voltages.
The comparator has 8 inputs multiplexed separately to its positive and negative inputs.
The multiplexers are controlled by the comparator register CTL (see
and
Input 0 of the multiplexers is the programmable voltage ladder output.
Bits 2:1 control the external inputs ACMP_I[2:1].
Bits 6 of the multiplexers controls internal reference voltage input.
Table 149. Analog comparator pin description
Function
Type Pin
Description
SWM register
Reference
ACMP_I1 I
PIO0_0/ACMP_I1
Comparator input 1
PINENABLE0
ACMP_I2 I
PIO0_0/ACMP_I2/CLKIN
Comparator input 2. Disable the CLKIN
function in the PINSASSIGN1BIT0
register.
PINENABLE0
ACMP_O O
any
Comparator output
PINASSIGN8
VDDCMP I
PIO0_6/VDDCMP
External reference voltage source for
32-stage Voltage Ladder.
PINENABLE0