4.3.11.1 Byte to Word Conversion

The dsPIC33A CPU has two instructions that are helpful when mixing 8, 16 and 32-bit ALU operations.

The Sign-Extend (SE) instruction takes a byte or word value in a W register or data memory and creates a sign-extended long word value that is stored in a W register.

The Zero-Extend (ZE) instruction takes a byte or word value in a W register or data memory and clears the 24 or 16 MSbs of a long word in a destination W register for an extend from 8 or 16 bits, respectively.