Texas Instruments MSP-FET430, User Manual

Page: 37 / 95

Design Considerations for In-Circuit Programming
3-7
3.5 Signal Connections for In-System Programming and Debugging, MSP-
FETP430IF, MSP-FET430UIF
With the proper connections, you can use the C-SPY debugger and an FET
hardware JTAG interface such as the MSP-FETP430IF and MSP-FET430UIF
to program and debug code on your own target board. In addition, the
connections will support the GANG430 or PRGS430, thus providing an easy
way to program prototype boards, if desired.
Figure 3-2 below shows the connections between the FET Interface module
and the target device required to support in-system programming and
debugging using C-SPY. The figure shows a 14-pin connected to the MSP430.
With this header mounted on your target board, the FET Interface module can
be plugged directly into your target. Then simply use C-SPY as you would
normally to program and debug.
The connections for the FET Interface module and the GANG430 or PRGS430
are identical. Both the FET Interface module and GANG430 can supply V
CC
to
your target board (via pin 2). In addition, the FET Interface module and
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, i.e., 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 utilizes 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 or the GANG430. If the V
CC
-sense
feature is not necessary (i.e., the target board is to be powered from the FET
Interface module or the GANG430) the V
CC
connection is made to pin 2 on the
JTAG header and no connection is made to pin 4. Figure 3-2 shows a jumper
block in use. The jumper block 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 eliminating the jumper block.