Design Considerations for In-Circuit Programming
3.5Signal 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 VCC to your target board (via pin 2). In addition, the FET Interface module and GANG430 have a VCC-sense feature that, if used, requires an alternate connection (pin 4 instead of pin 2). The VCC-sense feature senses the local VCC (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 VCC, then the connection to pin 4 on the JTAG should be made, and not the connection to pin 2. This utilizes the VCC-sense feature and prevents any contention that might occur if the local on-board VCC were connected to the VCC supplied from the FET Interface module or the GANG430. If the VCC-sense feature is not necessary (i.e., the target board is to be powered from the FET Interface module or the GANG430) the VCC 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 VCC to the target board. If this flexibility is not required, the desired VCC connections may be hard-wired eliminating the jumper block.