hpgl_xy/stm32f103c8t6-bootloader/src/usb_util.c

55 lines
No EOL
1.7 KiB
C

#include "usb_util.h"
void USB_PMAToMemory(void *mem, uint16_t offset, 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. This of course means
// that the target memory area must be of even length!
if(length & 1)
{
length++;
}
uint8_t *dst = (uint8_t*)mem;
uint8_t *pma = (uint8_t*)(USB_PMA_ADDR + 2 * offset);
for(unsigned int i = 0; i < length / 2; i++)
{
dst[2 * i] = *pma++;
dst[2 * i + 1] = *pma++;
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++;
}
}
void USB_SetEPR(volatile uint16_t *EPR, uint16_t status)
{
// Caution: This function does a read-modify-write and is prone to
// unexpected behaviour when there are transactions going one, because the
// register contents might change during the function's execution. Thus,
// only use this function in initialisation code!
volatile uint16_t v = *EPR;
status ^= v & (USB_EP0R_DTOG_RX | USB_EP0R_STAT_RX |\
USB_EP0R_DTOG_TX | USB_EP0R_STAT_TX);
*EPR = status;
}