I have the following code (that works)
; begin
ARRAY: .DB 22,34,56,21 ; define an array of byte
LDI ZL, LOW (2*ARRAY) ; point to address "array"
LPM ; read array[0] e store it in R0
; end
Why I must multiple by 2 the address ARRAY?
On help I read that since the register Z does a bytewise access (instead of a wordwise access) you must multiple by 2 the address.
But I didn't understand exactly the reason.
Thanks in advance
Look at the listing:
000002 ARRAY: .DB 22,34,56,21 000002 2216 000003 1538 000004 e0e4 LDI R30,LOW(2*ARRAY) 000005 95c8 LPMThe assembler used word addresses but you need a byte address for accessing program memeory with the LPM instruction.
A decent assembler would also use byte addresses (and calculate the word address for jumps):
00000004: 16 22 38 15 array: dc.b 22,34,56,21 00000008: e0e4 move.b #array,r30 0000000a: 95c8 movePM.b (r31|r30),r0Have something to add? Share your thoughts — no account required.
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