Question

Consider the following AVR Assembly Language Code which is passed through an assembler.

.include "m324Adef.inc"
    jmp RESET
    jmp HANDLER_1

.dseg
var1: .BYTE 2
var2: .BYTE 6


.cseg
const: .DB 0xAA, 0xCC, 0xDD

reset:
    ldi ZL, low(var1)
    ldi ZH, high(var1)
    ldi r17, 0xBB
    st Z, r17
    ldi ZL, low(const<<1)
    ldi ZH, high(const<<1)
    lpm
    jmp mainloop
.dseg
var3: .BYTE 4
.cseg
.org 0x15
mainloop:
    ldi r20, 0xF0
    ...

Determine the segments and values of each of the following symbols. (Enter the segment as either "cseg" or "dseg" - without the quotes. Enter the values as decimal integers.).

Symbol Segment Value var1 var3 reset const mainloop

Answer 1

Sy mbe segment va lue (deciml Var dsrg 2 var dseg resct cseg 2yD dseg (dofa segment) - Vamables ane declared ontains vaniable de tinitions de clane by .DATA C.dseg) Codk segment (Creg)- →Contains program ingbuctions. alo tafled as Text Segment, Whch ton tainj executable instnuc ons. rmdsetly deeloredl m segment In prgrom data vari, vars ahe dhnectly declaned in onst i al thoc at cade tment in gvrm pragram ain lop Symbli hove executable rode for Is tzu c fons

sy thybelg to tade tegrrent BYTE indk cates untigned integer SBYT indicates sned inter indk ates var has unigned inte vayz BYTE V cafs Voun3 is assigned hl:th integer y → Const: 'DK 0X AA , o XCC, CNDD ind, copies van assigned DB is used to기 allocat4n9 Hme than 1 Rfte hn sto ning values 62刀 Mo le Here the values ane eset inputs it pints h tmst value that 拜 170 (nem aining die al$01nted, using printers) Idi- lbad Tmwmediate StSt instuchan thrier in teger value and ov nei at specified mernory add기es!

has 16 bits 000000 oO ZL-8brt Const e/ bits z ZH二 00000000 2L - Lotwer order lett shif 2 L brtomes o 1 10 10 0000000 01 11010 tpm-) loads tne byte pointed by 2羽ilter to deshnatiun neg 1i ter. Ro Ipm load pragrom menmory) o, S oned at des hratio negi ten rs loaded ot egister r20