CODEWITHSUNDEEP
assemblypic
aod
aod

Reputation: 15

Crossing Page Boundaries in Program Memory

I need help with assembly codes and page crossing on program memory locations.

ORG  0x500;
BCF pclath,4;
BSF pclath,3;
CALL sub1_p1;
.
.
.
ORG 0x900;
sub1 :
 :
RETURN

If I want to cross page boundaries in program memory. For example page 0 to page 3. What code should I write?

Upvotes: 1

Views: 665

Answers (1)

GJ.
GJ.

Reputation: 10937

Bits 3 and 4 of PCLATH register determine the page number!

Examples: 

BCF  PCLATH,4 ;Select page0
BCF  PCLATH,3 ;Select page0
CALL xpage0
...
BCF  PCLATH,4 ;Select page 1
BSF  PCLATH,3 ;Select page 1
CALL xpage1
...
BSF  PCLATH,4 ;Select page2
BCF  PCLATH,3 ;Select page2
CALL xpage2
...
BSF  PCLATH,4 ;Select page 3
BSF  PCLATH,3 ;Select page 3
CALL xpage3
...

Newer PIC16xxx MCPUs use special instruction MOVLP.

Example: 

MOVLP high HiProc2
CALL  HiProc2
...

Upvotes: 1

Related Questions