Loading 16-bit Numbers into D and X Registers

[EvLer]

I need to read-in two 16-bit numbers from memory and divide one by the other. Well, i think i need to use FDIV instruction which would divide what's in D-register by what's in X-register, but i am stumped when it comes loading the data. Here's code we were given (commented is my solution)

        org     0800h
        ;ldd    ops
        ;ldx    ops (?)
        ;fdiv
        ;std    remain
        ;stx    quot
        stop   

ops      rmb     4
quot     rmb     2
remain  rmb     2

what bothers me is that rmb (reserve memory byte) is 4 which makes sense for 2 16-bit numbers but how do i load 2 separate 16-bit registers, so that first 2-bytes are loaded into D and second 2-bytes go into X?
D register will load 16 bits fine, but wouldn't X be loaded with the same 2 bytes? Technically i can figure out the address and load X with that address, but is there a "cleaner" way to do it?
thanks.

 

[berkeman]

Beats me. Can you provide pointers to the Assy language references please?

 

[EvLer]

Beats me. Can you provide pointers to the Assy language references please?

ummm... if you mean "references" it's CPU12 reference guide from freescale, http://www.freescale.com/webapp/sps...ce=68HC912B32&DocTypeKey=10Ksfwlk&Results=25"
but i think i got it last night: i loaded Y-register with the address of the "ops" and then used indexed addressing mode with constant offset to load the second number.
so my code changed like this:
ldx ops
ldy #ops
ldd 2,y
seems to work!
thanks anyway, berkeman!edit:
a follow-up question though: in assembly you can't just set a variable to a value, like you would in a high-level language, you always have to go through registers?
hope my question is clear

 

[berkeman]

a follow-up question though: in assembly you can't just set a variable to a value, like you would in a high-level language, you always have to go through registers?
hope my question is clear

Sure you can. Just look a little farther bud.

 

[mathmike]

for your first question can you use the co-processer registers or must you use only the main registers

 

[EvLer]

i assumed main registers... in 68HC12 we have x,y,d,sp,i,pc registers.

got it, berkeman