This section describes the instruction set for Microchip's PIC microcontrollers. It includes byte-oriented, bit-oriented, and literal/control instructions. Byte instructions operate on file registers and the working register W. Bit instructions manipulate individual bits. Literal instructions use constants. Most instructions execute in one cycle, but some that affect program flow take two cycles. Special function registers like the program counter and status register are discussed. The instruction set allows reading and writing all registers in a consistent orthogonal manner.