Hello Jan, > I need to do a bitmask on register. > > These are the constants, and mask > > $24 constant ddrb > $25 constant portb > > \ bit masks > %000100 constant mSS ( PB2 ) > %100000 constant mSCK ( PB5 ) > > I wont > 1. to set the bits in ddrb with the bitmask mSS > 2. to clear bits in portb with the bitmask mSCK > > In bitnames.frt there is a word bitmask: How can I use it to do > the two actions above? > > This is mor as a learning to understand working with bitmask. > > Thanks for any help.
There are only 4 lines of text in amforth/trunk/avr8/lib/bitnames.frt > \ multi bit operation > \ PORTD F bitmask: PD.F ( define the lower nibble of port d ) > \ PD.F pin@ ( get the lower nibble bits ) > \ 5 PD.F pin! ( put the lower nibble bits, do not change the > others ) There is a functional example on this page http://amforth.sourceforge.net/Projects/ClockWorks/08_timezones.html see "Code Details" and therein "Pins to select timezone" Well, in the end there are only 3 important lines: #include bitnames.frt \ define bits 0 and 1 of PORTA as a bitmask named _tz PORTA $03 bitmask: _tz \ set the pins as "input" _tz pin_input \ read the pins --- they are conncted to pullup resistors \ through switches _tz pin@ the result is either 0 1 2 or 3 in this particular case, depending on which of the two bits read as "1". Hope this helps, Erich -- May the Forth be with you ... _______________________________________________ Amforth-devel mailing list for http://amforth.sf.net/ Amforth-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/amforth-devel
