位带操作

tongye_admin

void * get_bit_band_addr(void * addr, int bit_index)
{
    u32 source_addr = (u32)addr;
    u32 base_addr = 0;
    u32 base_bit_band_addr = 0;
    if(source_addr < SRAM1_BASE)
    {
        base_addr = CCMDATARAM_BASE;
        base_bit_band_addr = CCMDATARAM_BB_BASE;
    }
    else if(source_addr < SRAM2_BASE)
    {
        base_addr = SRAM1_BASE;
        base_bit_band_addr = SRAM1_BB_BASE;
    }
    else if(source_addr < SRAM3_BASE)
    {
        base_addr = SRAM2_BASE;
        base_bit_band_addr = SRAM2_BB_BASE;
    }
    else if(source_addr < PERIPH_BASE)
    {
        base_addr = SRAM3_BASE;
        base_bit_band_addr = SRAM3_BB_BASE;
    }
    else if(source_addr < BKPSRAM_BASE)
    {
        base_addr = PERIPH_BASE;
        base_bit_band_addr = PERIPH_BB_BASE;
    }
    else
    {
        base_addr = BKPSRAM_BASE;
        base_bit_band_addr = BKPSRAM_BB_BASE;
    }

    return (void *)(base_bit_band_addr + ((source_addr - base_addr) << 5) + (bit_index << 2));
}