LM3S8G62 Datasheet, PDF (54/1096 Pages) Texas Instruments – Stellaris® LM3S8G62 Microcontroller

OBSOLETE: TI has discontinued production of this device.
Architectural Overview
1.3.6.2
1.3.7
– ADC module uses burst requests for DMA
Analog Comparators (see page 866)
An analog comparator is a peripheral that compares two analog voltages and provides a logical
output that signals the comparison result. The LM3S8G62 microcontroller provides two independent
integrated analog comparators that can be configured to drive an output or generate an interrupt or
ADC event.
The comparator can provide its output to a device pin, acting as a replacement for an analog
comparator on the board, or it can be used to signal the application via interrupts or triggers to the
ADC to cause it to start capturing a sample sequence. The interrupt generation and ADC triggering
logic is separate. This means, for example, that an interrupt can be generated on a rising edge and
the ADC triggered on a falling edge.
The LM3S8G62 microcontroller provides two independent integrated analog comparators with the
following functions:
■ Compare external pin input to external pin input or to internal programmable voltage reference
■ Compare a test voltage against any one of the following voltages:
– An individual external reference voltage
– A shared single external reference voltage
– A shared internal reference voltage
JTAG and ARM Serial Wire Debug (see page 165)
The Joint Test Action Group (JTAG) port is an IEEE standard that defines a Test Access Port and
Boundary Scan Architecture for digital integrated circuits and provides a standardized serial interface
for controlling the associated test logic. The TAP, Instruction Register (IR), and Data Registers (DR)
can be used to test the interconnections of assembled printed circuit boards and obtain manufacturing
information on the components. The JTAG Port also provides a means of accessing and controlling
design-for-test features such as I/O pin observation and control, scan testing, and debugging. Texas
Instruments replaces the ARM SW-DP and JTAG-DP with the ARM Serial Wire JTAG Debug Port
(SWJ-DP) interface. The SWJ-DP interface combines the SWD and JTAG debug ports into one
module providing all the normal JTAG debug and test functionality plus real-time access to system
memory without halting the core or requiring any target resident code. The SWJ-DP interface has
the following features:
■ IEEE 1149.1-1990 compatible Test Access Port (TAP) controller
■ Four-bit Instruction Register (IR) chain for storing JTAG instructions
■ IEEE standard instructions: BYPASS, IDCODE, SAMPLE/PRELOAD, EXTEST and INTEST
■ ARM additional instructions: APACC, DPACC and ABORT
■ Integrated ARM Serial Wire Debug (SWD)
– Serial Wire JTAG Debug Port (SWJ-DP)
– Flash Patch and Breakpoint (FPB) unit for implementing breakpoints
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July 24, 2012
Texas Instruments-Production Data