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How do you write the if else statement below in assembly languange?
C Code:
If ( input < WaterLevel)
{
MC = 1;
}
else if ( input == WaterLevel)
{
MC = 0;
}
Pseudocode
If input < Water Level
Send 1 to microcontroller
Turn Motor On
Else if input == Water Level
Send 0 to microcontroller
Turn Motor Off
Incomplete Assembly: (MC- Microcontroller)
CMP Input, WaterLevel
MOV word[MC], 1
MOV word[MC], 2
627
Consider the two examples presented above, they could be written in assembly language with the following code: // IF.. THEN..ELSE form: mov( i, eax ); test( eax, eax ); // Check for zero.
Use if to specify a block of code to be executed, if a specified condition is true. Use else to specify a block of code to be executed, if the same condition is false. Use else if to specify a new condition to test, if the first condition is false. Use switch to specify many alternative blocks of code to be executed.
It is generally used in conditional execution. This instruction basically subtracts one operand from the other for comparing whether the operands are equal or not. It does not disturb the destination or source operands. It is used along with the conditional jump instruction for decision making.
The jnz (or jne) instruction is a conditional jump that follows a test. It jumps to the specified location if the Zero Flag (ZF) is cleared (0). jnz is commonly used to explicitly test for something not being equal to zero whereas jne is commonly found after a cmp instruction.
If we want to do something in C like:
if (ax < bx)
{
X = -1;
}
else
{
X = 1;
}
it would look in Assembly like this:
cmp ax, bx
jl Less
mov word [X], 1
jmp Both
Less:
mov word [X], -1
Both:
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