On Thu, 12 Mar 1998 14:26:48 +0100 Morgan Olsson <mrt@INAME.COM> writes:
>At 12:18 1998-03-12 GMT, you wrote:

>The range of goto and call is called a page (2K area).  There is no
>other
>physical limit; the program area is continuous.  So you have to make
>sure
>you tell the assembler (using org command) to locate your program, and
>then
>ypu have to write code to change PCLATH when appropriate.


On a 71, 84, etc. with 2K or less of program memory you don't have to
deal with program memory pages other than using modify PCLs to access
tables.

>Reading tables using retlw you jump using "addwf PCL" to set the low 8
>bits
>of PC, and you have to make sure to set/have the whole PCLATH to form
>the
>upper adress first.

The simplest way to do this, if you don't have a lot of table data, is to
place all tables in the same 256-location page, e.g. from 0 to FF.  Then
be sure PCLATH is zero (or wherever the table page is) before trying to
access a table.  You can place org statements before and/or after the
table area to force the assembler to a fatal error (trying to put two
things in the same program memory location) if the tables won't fit in
the space allowed.


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