Texas Instruments MSP430 - Manual (Page 32)

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A.2 Known Issues
MSP-FET430PIF Some PCs do not supply 5 V through the parallel port
Problem Description Device identification problems with modern PCs, because the parallel port often does not
deliver 5 V as was common with earlier hardware.
1. When connected to a laptop, the test signal is clamped to 2.5 V.
2. When the external V
CC
becomes less than 3 V, up to 10 mA is flowing in the adapter
via pin 4 (sense).
Solution Measure the voltage level of the parallel port. If it is too low, provide external 5 V to the
V
CC
pads of the interface. The jumper on a the target socket must be switched to
external power.
MSP-FET430UIF Current detection algorithm of the UIF firmware
Problem Description If high current is detected, the I
CC
Monitor algorithm stays in a loop of frequently
switching on and off the target power supply. This power switching puts some MSP430
devices such as the MSP430F5438 in a state that requires a power cycle to return the
device to JTAG control.
A side issue is that if the UIF firmware has entered this switch on / switch off loop, it is
not possible to turn off the power supply to the target by calling MSP430_VCC(0). A
power cycle is required to remove the device from this state.
Solution IAR KickStart and Code Composer Essentials that have the MSP430.dll version
2.04.00.003 and higher do not show this problem. Update the software development tool
to this version or higher to update the MSP-FET430UIF firmware.
32 Frequently Asked Questions and Known Issues SLAU278F – May 2009 – Revised December 2010
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