P89LPC938 NXP Semiconductors, P89LPC938 Datasheet - Page 46

• Manufacturer Part Number: P89LPC938
• Description: The P89LPC938 is a single-chip microcontroller, available in low cost packages, based ona high performance processor architecture that executes instructions in two to four clocks,six times the rate of standard 80C51 devices
• Manufacturer: NXP Semiconductors

Philips Semiconductors
8. A/D converter
9397 750 14051
Product data sheet
7.29 User configuration bytes
7.30 User sector security bytes
8.1 General description
8.2 Features
Some user-configurable features of the P89LPC938 must be defined at power-up and
therefore cannot be set by the program after start of execution. These features are
configured through the use of the Flash byte UCFG1. Please see the P89LPC938 User’s
Manual for additional details.
There are eight User Sector Security Bytes on the P89LPC938. Each byte corresponds to
one sector. Please see the P89LPC938 User’s Manual for additional details.
The P89LPC938 has a 10-bit, 8-channel multiplexed successive approximation
analog-to-digital converter module. A block diagram of the A/D converter is shown in
Figure
circuit providing an input signal to one of two comparator inputs. The control logic in
combination with the SAR drives a digital-to-analog converter which provides the other
input to the comparator. The output of the comparator is fed to the SAR.
10-bit, 8-channel multiplexed input, successive approximation A/D converter.
Eight result register pairs.
Six operating modes
Three conversion start modes
10-bit conversion time of 4 s at an A/D clock of 9 MHz
Interrupt or polled operation
High and Low Boundary limits interrupt; selectable in or out-of-range
Clock divider
Power-down mode
Fixed channel, single conversion mode
Fixed channel, continuous conversion mode
Auto scan, single conversion mode
Auto scan, continuous conversion mode
Dual channel, continuous conversion mode
Single step mode
Timer triggered start
Start immediately
Edge triggered
21. The A/D consists of an 8-input multiplexer which feeds a sample-and-hold
Rev. 01 — 25 February 2005
8-bit microcontroller with 10-bit A/D converter
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
P89LPC938
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