LM3S1G21 Datasheet, PDF (51/955 Pages) Texas Instruments – Stellaris® LM3S1G21 Microcontroller

Stellaris^® LM3S1G21 Microcontroller
1.3.7
1.3.8
The LM3S1G21 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 161)
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
– Data Watchpoint and Trace (DWT) unit for implementing watchpoints, trigger resources, and
system profiling
– Instrumentation Trace Macrocell (ITM) for support of printf style debugging
– Trace Port Interface Unit (TPIU) for bridging to a Trace Port Analyzer
Packaging and Temperature
■ Industrial-range (-40°C to 85°C) 100-pin RoHS-compliant LQFP package
■ Industrial-range (-40°C to 85°C) 108-ball RoHS-compliant BGA package
January 22, 2012
51
Texas Instruments-Production Data