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Bits to Hex?

Lorenzo D

Hi all,

I need a little assistance wrapping my head around this issue. It's not strictly an arm/cortex problem, so everyone feel free to chime in! Anyways, to the issue...

I am receiving serial data at one of the pins on my microcontroller. So for example, at PA0 (port A, pin 0), I might get a feed of 010010000. What is the best way to accept this data/modify it so that I can transmit it through UART.

My current method was to create an 8 array element, and then saving each value. But I don't think that would work because an 8 array element does not necessarily mean 8 bits, which is what my UART is setup to transmit... I'm not sure what the best way would be to handle this problem. Any help would be appreciated, thanks!

Parents
  • 0

    You can use a "bit array":

    #define BITMASK(b)      (1 << ((b) % CHAR_BIT))
#define BITSLOT(b)      ((b) / CHAR_BIT)
#define BITSET(a, b)    ((a)[BITSLOT(b)] |= BITMASK(b))
#define BITCLEAR(a, b)  ((a)[BITSLOT(b)] &= ~BITMASK(b))
#define BITTEST(a, b)   ((a)[BITSLOT(b)] & BITMASK(b))
#define BITNSLOTS(nb)   ((nb + CHAR_BIT - 1) / CHAR_BIT)

    and

    // bit array to indicate, per block, whether it is defective of not (either established by factory data, runtime
// verification or NAND flash operation failing
int8u        g_nand_flash_defective_physical_blocks[BITNSLOTS(NANDFLASH_BLOCKNUM)] ;
.
.
.
BITSET(g_nand_flash_defective_physical_blocks, l_physical_block ) ;
.
.
.
if ( (BITTEST(g_nand_flash_defective_physical_blocks, l_physical_block) == 0) &&
                 (BITTEST(g_nand_flash_allocated_physical_blocks, l_physical_block) == 0) )
.
.
.

Reply
  • 0

    You can use a "bit array":

    #define BITMASK(b)      (1 << ((b) % CHAR_BIT))
#define BITSLOT(b)      ((b) / CHAR_BIT)
#define BITSET(a, b)    ((a)[BITSLOT(b)] |= BITMASK(b))
#define BITCLEAR(a, b)  ((a)[BITSLOT(b)] &= ~BITMASK(b))
#define BITTEST(a, b)   ((a)[BITSLOT(b)] & BITMASK(b))
#define BITNSLOTS(nb)   ((nb + CHAR_BIT - 1) / CHAR_BIT)

    and

    // bit array to indicate, per block, whether it is defective of not (either established by factory data, runtime
// verification or NAND flash operation failing
int8u        g_nand_flash_defective_physical_blocks[BITNSLOTS(NANDFLASH_BLOCKNUM)] ;
.
.
.
BITSET(g_nand_flash_defective_physical_blocks, l_physical_block ) ;
.
.
.
if ( (BITTEST(g_nand_flash_defective_physical_blocks, l_physical_block) == 0) &&
                 (BITTEST(g_nand_flash_allocated_physical_blocks, l_physical_block) == 0) )
.
.
.

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