I am currently using the parallel to output data prepared by the HC11. As well, I am attempting to use the STAF (Strobe A Flag) bit to control the flow of data. The problem is when I try to clear the STAF bit according to the Motorola Reference Manual (ie. read the PIOC, then read the PORTCL register), the microcontroller freezes. Yet, when I do not clear it the microcontroller continues to output data as expected. Can anyone help?