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the oscillator calibration word programmed by the factory into some
devices. Chapter 7 / Programming the PIC16F876 Microcontroller
The Erase speed button will erase EEPROM or flash electrically erasa-
ble devices. It is grayed out for devices that cannot be electrically
erased.
The Device box allows selection of the device to be programmed. Click
the down arrow to the right of the box to drop down a list of support-
ed devices, then click on the device. This device information, includ-
ing the default device that is selected on start-up, is contained in the
file EPIC.INI. This file must be in the same directory as EPICWIN.EXE.
Select the device before a .HEX file is opened to ensure the configura-
tion information is properly interpreted. Devices with parentheses
after them indicate that they will program either the base version of
the part, or the version contained within the parentheses. For exam-
ple, selecting the device listed as PIC16F84(A) means that either the
PIC16F84 or the PIC16F84A may be programmed.
All of the speed buttons, along with other settings, are also available
using the drop-down menus.

The PICmicro MCU Compiler

The code for PIC16F876 used in PDA Robot was compiled using the
PICmicro MCU compiler. The code is written in C, and will be
explained in detail in this chapter.
The PCM compiler is for 14-bit opcodes, and PCH is for the 16- and
18-bit PICmicro MCU. This compiler is specially designed to meet the
special 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 tradi-
tional 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 decid-
ing how to best implement your algorithms. The compilers can imple-

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