The PCB, PCM, and PCH are separate compilers.  PCB is for 12-bit opcodes, PCM is for 14-bit opcodes, and PCH is for 16-bit opcode PIC® microcontrollers.  Due to many similarities, all three compilers are covered in this reference manual.  Features and limitations that apply to only specific microcontrollers are indicated within.  These compilers are specifically designed to meet the unique needs of the PIC® microcontroller.  This allows developers to quickly design applications software in a more readable, high-level language.