Assembly language variables

Question

What is the assembly language variable bl? How many bits does it hold? Is it a part of a larger variable like EBX?

I'm running on a PC, not sure what architecture that's called. So does bl show a part of a register? — neuromancer
– neuromancer, Commented May 19, 2010 at 12:12
@ThiefMaster: registers are a type of variable, or most accurately, 'EBX' in assembly language is a variable that's implemented by the register called 'EBX'. — Joren
– Joren, Commented May 19, 2010 at 20:25

C.Evenhuis · Accepted Answer · 2010-05-19 12:12:32Z

7

EBX is the 32-bit variant

BX is the 16-bit variant

BH is the high byte of BX

BL is the low byte of BX

answered May 19, 2010 at 12:12

C.Evenhuis

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4 Comments

So if EBX=0000001B, then what is bl?

1B is 32 bits, correct? Since each digit can go from 0 to F, which is 16 numbers. Does that mean that bl is a 32-bit variable?

@Phenom:No. Each hex digit can go from 0 to F. 16 numbers fit into 4 bits (2**4 = 16), so two hex digits correspond to 8 bits.

EBX = 00000000 00000000 00000000 00000000