hpgl_xy/stm32f103c8t6/src/usb_util.c

38 lines
927 B
C

#include "usb_util.h"
void USB_PMAToMemory(void *mem, uint16_t offset, size_t length)
{
uint8_t *dst = (uint8_t*)mem;
uint8_t *pma = (uint8_t*)(USB_PMA_ADDR + 2 * offset);
for(unsigned int i = 0; i < length; i++)
{
*dst++ = *pma++;
if(i & 1)
{
pma += 2;
}
}
}
void USB_MemoryToPMA(uint16_t offset, const void *mem, size_t length)
{
// Only words can be copied. Thus, if the length is not even, it has to be
// incremented to ensure that the last byte is copied. Since the PMA buffer
// always has even size, this is not a problem.
if(length & 1)
{
length++;
}
const uint8_t *src = (const uint8_t*)mem;
uint16_t *pma = (uint16_t*)(USB_PMA_ADDR + 2 * offset);
for(unsigned int i = 0; i < length / 2; i++)
{
uint16_t tmp = src[2 * i] | (src[2 * i + 1] << 8);
*pma++ = tmp;
pma++;
}
}