2.1 Signal Connections for In-System Programming and Debugging
MSP-FET430PIF, MSP-FET430UIF, MSP-GANG, MSP-GANG430, MSP-PRGS430
With the proper connections, the debugger and an FET hardware JTAG interface (such as the MSP-FET430PIF
and MSP-FET430UIF) can be used to program and debug code on the target board. In addition, the connections
also support the MSP-GANG430 or MSP-PRGS430 production programmers, thus providing an easy way to
program prototype boards, if desired.
shows the connections between the 14-pin FET interface module connector and the target device
required to support in-system programming and debugging for 4-wire JTAG communication.
shows
the connections for 2-wire JTAG mode (Spy-Bi-Wire). The 4-wire JTAG mode is supported on most MSP430
devices, except devices with low pin counts (for example, MSP430G2230). The 2-wire JTAG mode is available
on selected devices only. See the
Code Composer Studio IDE for MSP430 MCUs User's Guide
or
Embedded Workbench IDE for MSP430 MCUs User's Guide
for information on which interface method can be
used on which device.
The connections for the FET interface module and the MSP-GANG, MSP-GANG430, or MSP-PRGS430 are
identical. Both the FET interface module and MSP-GANG430 can supply V
CC
to the target board (through pin 2).
In addition, the FET interface module, MSP-GANG, and MSP-GANG430 have a V
CC
-sense feature that, if used,
requires an alternate connection (pin 4 instead of pin 2). The V
CC
-sense feature senses the local V
CC
present on
the target board (that is, a battery or other local power supply) and adjusts the output signals accordingly. If the
target board is to be powered by a local V
CC
, then the connection to pin 4 on the JTAG should be made, and not
the connection to pin 2. This uses the V
CC
-sense feature and prevents any contention that might occur if the
local on-board V
CC
were connected to the V
CC
supplied from the FET interface module, MSP-GANG or the
MSP-GANG430. If the V
CC
-sense feature is not necessary (that is, if the target board is to be powered from the
FET interface module, MSP-GANG, or MSP-GANG430), the V
CC
connection is made to pin 2 on the JTAG
header, and no connection is made to pin 4.
show a jumper block that supports both
scenarios of supplying V
CC
to the target board. If this flexibility is not required, the desired V
CC
connections may
be hard-wired to eliminate the jumper block. Pins 2 and 4 must not be connected at the same time.
The connection to the JTAG connector RST pin of
is required when programming or debugging a
device that supports 2-wire JTAG communication, even when using 4-wire JTAG communication mode on these
devices. However, this connection is optional on devices that do not support 2-wire JTAG communication. The
MSP430 development tools and device programmers perform a target reset by issuing a JTAG command to gain
control over the device. However, if this is unsuccessful, the RST signal of the JTAG connector may be used by
the development tool or device programmer as an additional way to assert a device reset.
Design Considerations for In-Circuit Programming
20
MSP430™ Hardware Tools
SLAU278AG – MAY 2009 – REVISED DECEMBER 2020
Copyright © 2020 Texas Instruments Incorporated
