LPC MicrocontrollersのトピックRe: memcpy struct to array

memcpy struct to array

lpcware — Wed, 15 Jun 2016 17:45:33 GMT

Content originally posted in LPCWare by terrype on Sun Nov 23 20:57:58 MST 2014
Dear Friends,
struct
{
unsigned char x1;
unsigned char y1;
unsigned int    z1;
}abc1;

struct
{
unsigned char x2;
unsigned char y2;
unsigned int    z2;
struct abc1        lpc1;
}abc2;

struct
{
unsigned char x2;
struct abc2        lpc2;

}abc3;

unsigned char   test[256];
strcut abc3    test_abc;

memcpy(test, test_abc, sizeof(struct abc3));

when i call this function, it copies struct test_abc to test with additional byte 00 aftre lpc1, is any one facing this issue?

Re: memcpy struct to array

lpcware — Wed, 15 Jun 2016 17:45:34 GMT

Content originally posted in LPCWare by MikeSimmonds on Sun Nov 23 22:01:56 MST 2014
Might be down to struckure packing.
Mike

Re: memcpy struct to array

lpcware — Wed, 15 Jun 2016 17:45:35 GMT

Content originally posted in LPCWare by lpcxpresso-support on Mon Nov 24 01:16:25 MST 2014
See this FAQ:
http://www.lpcware.com/content/faq/lpcxpresso/packed-structures

Re: memcpy struct to array

lpcware — Wed, 15 Jun 2016 17:45:35 GMT

Content originally posted in LPCWare by terrype on Mon Nov 24 16:01:31 MST 2014
Thanks guys,
For lpcexpresso users

#if defined(__GNUC__)
#define PRE_PACK
#define POST_PACK__attribute__((__packed__))
#define ALIGNED(n)      __attribute__((aligned (n)))
#endif

PRE_PACK struct POST_PACK    __FOO__
{
uint8_t L; /**< lower byte */
uint8_t H; /**< upper byte */
};
/** Structure to pack lower and upper byte to form 16 bit word.*/
typedef struct __FOO__    FOO;