Texas Instruments Stellaris LM3S2965, Руководство пользователя, Страница: 14 / 32

Hardware Description
14 January 6, 2010
Power Supplies
The LM3S2965 is powered from a +3.3-V supply. A low drop-out (LDO) regulator reg5-V
power from the USB cable to +3.3-V. +3.3-V power is available for powering external circuits.
A +15-V rail is available when the OLED display is active. The speaker and OLED display boost-
converter operate directly from the +5-V rail.
Debugging
Stellaris microcontrollers support programming and debugging using either JTAG or SWD. JTAG
uses the signals
TCK
,
TMS
,
TDI
, and
TDO
. SWD requires fewer signals (
SWCLK
,
SWDIO
, and,
optionally,
SWO
, for trace). The debugger determines which debug protocol is used.
Debugging Modes
The LM3S2965 evaluation board supports a range of hardware debugging configurations. Table
summarizes these.
Modes 2 and 3 automatically detect the presence of an external debug cable. When the debugger
software is connected to the EVB's USB controller, the EVB automatically selects Mode 2 and
illuminates the red Debug Out LED. ICDI out (Mode 2) can be used to program and debug the
small LM3S2110 CAN device board included in the kit.
Debug In Considerations
Debug Mode 3 supports evaluation board debugging using an external debug interface. Mode 3 is
automatically selected when a device such as a Segger J-Link or Keil ULINK is connected.
Boards marked Revision C or later automatically configure pin 1 to be a 3.3-V reference, if an
external debugger is connected. To determine the revision of your board, locate the product
number on the bottom of the board; for example, EK-LM3S2965-C. The last character of the
product number identifies the board revision.
A configuration or board-level change may be necessary when using an external debug interface
with revisions A and B of this evaluation board. Because the evaluation board supports both debug
out and debug in modes, pin 1 of the 20-pin JTAG/SWD header is, by default, not connected to
+3.3 V. Consequently, devices requiring a voltage on pin 1 to power their line buffers may not
work.
Table 2-1. Stellaris LM3S2965 Evaluation Board Hardware Debugging Configurations
Mode Debug Function Use Selected by
1 Internal ICDI Debug on-board LM3S2965
microcontroller over USB
interface. Default mode
2 ICDI out to JTAG/SWD header The EVB is used as a USB
to SWD/JTAG interface to
an external target. Connecting to an external
target and starting debug
software. The red Debug
Out LED will be ON.
3 In from JTAG/SWD header For users who prefer an
external debug interface
(ULINK, JLINK, etc.) with the
EVB. Connecting an external
debugger to the JTAG/SWD
header