LM3S6422 Luminary Micro, Inc, LM3S6422 Datasheet - Page 34

• Manufacturer Part Number: LM3S6422
• Description: Lm3s6422 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

Architectural Overview
1.4.7
1.4.7.1
1.4.7.2
1.4.7.3
1.4.8
34
Additional Features
Memory Map (see page 41)
A memory map lists the location of instructions and data in memory. The memory map for the
LM3S6422 controller can be found in “Memory Map” on page 41. Register addresses are given as
a hexadecimal increment, relative to the module's base address as shown in the memory map.
The ARM® Cortex™-M3 Technical Reference Manual provides further information on the memory
map.
JTAG TAP Controller (see page 46)
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.
The JTAG port is composed of the standard five pins: TRST, TCK, TMS, TDI, and TDO. Data is
transmitted serially into the controller on TDI and out of the controller on TDO. The interpretation of
this data is dependent on the current state of the TAP controller. For detailed information on the
operation of the JTAG port and TAP controller, please refer to the IEEE Standard 1149.1-Test
Access Port and Boundary-Scan Architecture.
The Luminary Micro JTAG controller works with the ARM JTAG controller built into the Cortex-M3
core. This is implemented by multiplexing the TDO outputs from both JTAG controllers. ARM JTAG
instructions select the ARM TDO output while Luminary Micro JTAG instructions select the Luminary
Micro TDO outputs. The multiplexer is controlled by the Luminary Micro JTAG controller, which has
comprehensive programming for the ARM, Luminary Micro, and unimplemented JTAG instructions.
System Control and Clocks (see page 57)
System control determines the overall operation of the device. It provides information about the
device, controls the clocking of the device and individual peripherals, and handles reset detection
and reporting.
Hardware Details
Details on the pins and package can be found in the following sections:
■
■
■
■
■
“Pin Diagram” on page 409
“Signal Tables” on page 411
“Operating Characteristics” on page 435
“Electrical Characteristics” on page 436
“Package Information” on page 449
Preliminary
July 25, 2008