These macros decode data values from any CPU memory address.
Files
lib_mem.h
Prototypes
Arguments
addr
Lowest CPU memory address of the data value to decode.
Returned Value
Decoded data value from CPU memory address.
Required Configuration
None.
Notes / Warnings
CPU memory addresses/pointers not checked for NULL.
Decode data values based on the values’ data-word order in CPU memory:
MEM_VAL_GET_xxx_BIG()
Decode big-endian data values — data words’ most significant octet at lowest memory address
MEM_VAL_GET_xxx_LITTLE()
Decode little-endian data values — data words’ least significant octet at lowest memory address
MEM_VAL_GET_xxx()
Decode data values using CPU’s native or configured data-word order
MEM_VAL_GET_xxx() macros decode data values without regard to CPU word-aligned addresses. Thus for processors that require data word alignment, data words can be decoded from any CPU address, word-aligned or not, without generating data-word-alignment exceptions/faults. However, any variable to receive the returned data value must start on an appropriate CPU word-aligned address.
MEM_VAL_COPY_GET_xxx() macros are more efficient than MEM_VAL_GET_xxx() macros and are also fully independent of CPU data-word-alignment and should be used whenever possible.
MEM_VAL_GET_xxx() macros are not atomic operations and must not be used on any non-static (i.e., volatile) variables, registers, hardware, etc.; without the caller of the macros providing some form of additional protection (e.g. mutual exclusion).