SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
Load Halfword from Memory with a SP-Relative 19-Bit Unsigned Constant Offset
LDH *+SP[ucst19], dst
or
LDHU *+SP[ucst19], dst
Functional unit = D
32 bit
31 | 16 | 15 | 13 | 12 | 10 | 9 | 0 |
ucst19 | dst | ucst19 | opcode |
16 | 3 | 3 | 10 |
Syntax | Opcode | Load Type |
---|---|---|
LDH *+SP[ucst19], dst | 01 1000 0111 | Load halfword (sign-extended) |
LDHU *+SP[ucst19], dst | 00 1000 0111 | Load halfword unsigned (zero-extended) |
Loads a halfword (signed or unsigned) from memory (effective address) to dst. The memory address is formed from the stack pointer (SP) and an offset (number of halfwords) that is a 19-bit unsigned constant (ucst19). If an offset is not given, the assembler assigns an offset of zero. Brackets, [ ],must surround the specified offset, if using the optional offset parameter.
The square brackets, [ ], indicate that the ucst19 is scaled by a left-shift of 1 bit. After scaling, ucst19 is added to SP. The result of the calculation is the effective address to be accessed in memory and the content loaded into dst.
The content is loaded into the 16 LSBs of dst. For the LDH instruction, the upper 16 bits of dst are sign-extended; for the LDHU instruction, the upper 16 bits of dst are zero-extended.
Halfword addresses must be aligned on halfword (LSB is 0) boundaries.
None
dst = *(SP[ucst19])