Absolute maximum current from an I/O pin is not specified
for the MSP430. See the datasheet specifications for Voh and Vol.
They show that each I/O pin can supply several milliamps, but the
output voltage will change as the current increases. Footnotes
for those specifications generally give the maximum total currents,
from all outputs combined, that allow the specified voltages to
be maintained. MSP430 I/O are not designed to drive high-current
20mA LEDs.