At 12:50 PM 4/25/2012, Jan-Erik Soderholm wrote:
> >
> > setbsrbit       MACRO   target, bnum    ;bit
> >       movlb       (target>>7)            ;get bank bits
> > CURRBANK        set ((target>>7)<<7)  ;
> >       endm
> >
>
>OK. I'm lost... :-)
>
>What does the bnum parameter do ?

Its a throw-away parameter.

My include files are all in the form of:

; INTCON Register Bits          rb 0
     #define _IOCIF  INTCON,0    ; InterruptOnChange flag            rst in=
 sw
     #define _INTF   INTCON,1    ; RB0 INT interrupt flag            rst in=
 sw
     #define _T0IF   INTCON,2    ; TMR0 overflow int flag            rst in=
 sw
     #define _IOCIE  INTCON,3    ; InterruptOnChange Enable          active=
 hi
     #define _INTE   INTCON,4    ; INTF interrupt enable             active=
 hi
     #define _T0IE   INTCON,5    ; TMR0 interrupt enable             active=
 hi
     #define _PEIE   INTCON,6    ; Peripheral Interrupt Enable       active=
 hi
     #define _GIE    INTCON,7    ; global interrupt enable           active=
 hi

INT_INIT        EQU b'11000000' ;GIE, PEI enabled
INT_SLEEP       EQU b'00011000' ;wake up from i/p & pin change (no GIE)

This allows me to manipulate bits without ever knowing or caring in=20
which register the bit belongs to.

For example:
     bsf    _GIE
;next line of code


Another example, this time using the above macro:

;EECON1                         rb 3
     #define _RD     EECON1,0    ; Read: 1=3D initiate read
     #define _WR     EECON1,1    ; Write: 1=3D initiate write
     #define _WREN   EECON1,2    ; Erase/Write enable: 1=3Denable
     #define _WRER   EECON1,3    ; Erase/Write error: 1=3Derror
     #define _FREE   EECON1,4    ; Erase/Write select: 1=3DErase, 0=3DWrite
     #define _LWLO   EECON1,5    ; Ld Wr Latches Only =3D1; 0=3D Write all =
data
     #define _CFGS   EECON1,6    ; Config Select =3D1; 0=3D access Program =
memory
     #define _EEPGD  EECON1,7    ;

     movlw  MAGIC_VALUE_ADDRESS
     setbsr  EEADRL
     movwf   RB(EEADRL)
     clrf    RB(EEADRH)

;somewhere later in the code, now I want to read that value.  I have=20
no idea of what value BSR contains, so I need to set up the BSR=20
register.  Because I'm lazy, I don't want to go and find out what=20
register the "_RD" bit belongs to.  So I use the macro:

     setbsrbit  (_RD)
     bsf    BB(_RD)

Note how "_RD" expands to EECON1,0  - this means that the macro has=20
two parameters passed to it.  Since all I want is the bank in which=20
the register belongs to, I simply throw away the second=20
parameter.  But the macro has to be written to accept that second=20
parameter, else the assembler gets mad at you and throws a fatal error.

[RANT ON]

Why doesn't everyone write code using #define statements like I've=20
shown above.  It seems, to me, to be completely ridiculous that=20
people have to string register names and bit names together to do a=20
simple bit manipulation.  This is the new millennium, for gosh sakes!

One of the smartest people I've ever had the pleasure to learn from=20
(Andrew Warren) showed me the above technique and I've been using it=20
ever since.  That's back to the late '80s, early '90s.

[RANT OFF]

dwayne

--=20
Dwayne Reid   <dwayner@planet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(780) 489-3199 voice          (780) 487-6397 fax
www.trinity-electronics.com
Custom Electronics Design and Manufacturing

--=20
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