diff options
Diffstat (limited to 'examprep/bin/main.dbg')
| -rw-r--r-- | examprep/bin/main.dbg | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/examprep/bin/main.dbg b/examprep/bin/main.dbg new file mode 100644 index 0000000..cd3eb3d --- /dev/null +++ b/examprep/bin/main.dbg @@ -0,0 +1,65 @@ +************************************************************************** +* Parameter Declearation Section +* +* Export Symbols + xdef pgstart ; export 'pgstart' symbol + absentry pgstart ; for assembly entry point + +* Symbols and Macros +PORTA equ $0000 ; i/o port A addresses +DDRA equ $0002 ; data direction register for PORTA +PORTB equ $0001 ; i/o port B addresses +DDRB equ $0003 ; data direction register for PORTB + +************************************************************************** +* Data Section: address used [ $3000 to $30FF ] RAM Memory +* + org $3000 ; Reserved RAM memory starting address + ; for Data for CMPEN 472 class +SOURCE ds.b $000C ; 12 Byte source array + +LENSRC dc.w $000C ; Length of the Source Array + +DEST ds.b $000C ; 12 Byte destination array + +LENDST dc.w $000C ; Length of the destination array + +StackSP dc.w $3100 ; Address of the stack + +* +************************************************************************** +* Program Section: address used [ $3100 to $3FFF ] RAM Memory +* + org $3100 ; Program start address, in RAM +pgstart lds StackSP ; initialize the stack pointer + ldaa #1 ; Load 1 into A + ldx #SOURCE ; Load the address of SOURCE into X + ldy LENSRC ; Load the length of SOURCE into Y +fillLoop tbeq Y,doneLoop ; If Y==0, jump to done loop + staa 1,X+ ; Copy A into address of X, add 1 to X + inca ; Increment A by 1 + dey ; Decrement Y by 1 + bra fillLoop ; Jump to fillLoop +doneLoop jsr memcpy ; Call memcpy + bra done + + +memcpy pshy ; Save Y to the stack + pshx ; Save X to the stack + pshd ; Save D to the stack + ldy #SOURCE ; Load the address of the source array into Y + ldx #DEST ; Load the address of the destination array into X + ldd LENSRC ; Load the length of the source array into D +loop tbeq D,EXIT ; If d==0, jump to EXIT + movb Y,X ; Copy data from address in Y to address in X + inx ; Increment X by 1 + iny ; Increment Y by 1 + subd #1 ; Decrement D by 1 + bra loop ; Branch always to loop +EXIT puld ; Restore D from the stack + pulx ; Restore X from the stack + puly ; Restore Y from the stack + rts ; Return to caller + + +done |