Там все по-Англицки. А что конкретно интересует-то? Вот из описания: PCB, PCM and PCH Overview
The PCB, PCM and PCH are separate compilers. PCB is for 12 bit opcodes, PCM is for 14 bit opcodes and PCH is for the 16 and 18 bit PICmicro® MCU. Since much is in common among the compilers, all three are covered in this reference manual. Features and limitations that apply to only specific controllers are indicated within. These compilers are specially designed to meet the unique needs of the PICmicro® MCU controllers. These tools allow developers to quickly design application software for these controllers in a highly readable, high-level language.
The compilers have some limitations when compared to a more traditional C compiler. The hardware limitations make many traditional C compilers ineffective. As an example of the limitations, the compilers will not permit pointers to constant arrays. This is due to the separate code/data segments in the PICmicro® MCU hardware and the inability to treat ROM areas as data. On the other hand, the compilers have knowledge about the hardware limitations and do the work of deciding how to best implement your algorithms. The compilers can efficiently implement normal C constructs, input/output operations and bit twiddling operations.