Mikroelektronika MIKROE-350 データシート

490

- SOFTWARE AND HARDWARE SOLUTIONS FOR EMBEDDED WORLD

CHAPTER 6

sub function memcmp(dim p1, p2 as ^byte, dim n as word) as integer

The function returns a positive, negative, or zero value indicating the relation-
ship of first n words of memory areas starting at addresses 

p1

and 

p2

.

This function compares two memory areas starting at addresses 

p1

and 

p2

for n

words and returns a value indicating their relationship as follows:

< 0       p1 "less than" p2

= 0       p1 "equal to" p2

> 0       p1 "greater than" p2

The value returned by the function is determined by the difference between the
values of the first pair of words that differ in the strings being compared.

For parameters 

p1

and 

p2

you can use either a numerical value (literal/vari-

able/constant) indicating memory address or a dereferenced value of an object,
for example 

@mystring

or 

@PORTB

.

sub procedure memcpy(dim p1, p2 as ^byte, dim nn as word)

The function copies nn words from the memory area starting at the address 

p2

to the memory area starting at 

p1

. If these memory buffers overlap, the memcpy

function cannot guarantee that words are copied before being overwritten. If
these buffers do overlap, use the memmove function.

For parameters 

p1

and 

p2

you can use either a numerical value (literal/vari-

able/constant) indicating memory address or a dereferenced value of an object,
for example 

@mystring

or 

@PORTB

.

sub procedure memmove(dim p1, p2, as ^byte, dim nn as word)

The function copies nn words from the memory area starting at the address 

p2

to the memory area starting at 

p1

. If these memory buffers overlap, the 

Memmove

function ensures that the words in 

p2

are copied to 

p1

before being overwritten.

For parameters 

p1

and 

p2

you can use either a numerical value (literal/vari-

able/constant) indicating memory address or a dereferenced value of an object,
for example 

@mystring

or 

@PORTB

.