ARM and Thumb instructions can only be 32-bits wide. You can use the MOV and MVN instructions to load a register with an immediate value supported by the instruction set. Certain 32-bit values cannot be represented as an immediate operand to a single 32-bit instruction. These values can be loaded from memory in a single instruction.

In ARMv6T2 and later, you can load any 32-bit immediate value into a register with two instructions, a MOV followed by a MOVT. You can use a pseudo-instruction, MOV32, to construct the instruction sequence for you.

You can also use the LDR pseudo-instruction to load immediate values into a register.

You can include many commonly-used immediate values directly as operands within data processing instructions, without a separate load operation. The range of immediate values that you can include as operands in 16-bit Thumb instructions is much smaller.