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remove caching

This commit is contained in:
devsaurus 2015-03-01 23:45:25 +01:00
parent 32774d428c
commit 5f1d324059
1 changed files with 2 additions and 15 deletions
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17
app/modules/u8g.c
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@ -35,28 +35,15 @@ typedef struct _lu8g_userdata_t lu8g_userdata_t;
//};
static uint32_t *u8g_pgm_cached_iadr = NULL;
static uint32_t u8g_pgm_cached_data;
// function to read 4-byte aligned from program memory AKA irom0
u8g_pgm_uint8_t ICACHE_FLASH_ATTR u8g_pgm_read(const u8g_pgm_uint8_t *adr)
{
uint32_t iadr = (uint32_t)adr;
// set up pointer to 4-byte aligned memory location
uint32_t *ptr = (uint32_t *)(iadr & ~0x3);
uint32_t pgm_data;
if (ptr == u8g_pgm_cached_iadr)
{
pgm_data = u8g_pgm_cached_data;
}
else
{
// read 4-byte aligned
pgm_data = *ptr;
u8g_pgm_cached_iadr = ptr;
u8g_pgm_cached_data = pgm_data;
}
// read 4-byte aligned
uint32_t pgm_data = *ptr;
// return the correct byte within the retrieved 32bit word
return pgm_data >> ((iadr % 4) * 8);