16f877a CPU configuration

Each attribute in the configuration table below has two or more possible values associated with it.

e.g. the watchdog attribute (labelled field H ) has the possible values

one and only one of these values must be specified when configuring the CPU

The 16f877a CPU has 9 configuration attributes (labelled field A to I in the table below). The attributes specific to the 16f877a CPU are defined in the file hwreg-p16f877a.h To correctly configure the 16f877a CPU each attribute must be set to a valid value. This is done by using one "pragma cpu_config" statement per attribute. A valid configuration for 16f877a would look like:

e.g.
	include "hwreg-p16f877a.h"

	pragma cpu_config CFG_CP_ALL
	pragma cpu_config CFG_WRT_OFF
	pragma cpu_config CFG_DEBUG_ON
	pragma cpu_config CFG_CPD_ON
	pragma cpu_config CFG_LVP_ON
	pragma cpu_config CFG_BODEN_ON
	pragma cpu_config CFG_PWRTE_ON
	pragma cpu_config CFG_WDT_ON
	pragma cpu_config CFG_RC_OSC

NOTE: All attributes for a given processor must be specified, attributes for different processors may not be mixed.

Field
Attribute
XCSB value
Description
A
Program Memory Code Protect CFG_CP_ALL code protect all program memory
CFG_CP_OFF do not code protect any program memory
B
Program memory write protect CFG_WRT_OFF No prog memory write protection
CFG_WRT_256 First 256 prog memory write protected
CFG_WRT_1FOURTH First quarter prog memory write protected
CFG_WRT_HALF First half memory write protected
C
In Circuit Debugging CFG_DEBUG_ON In Circuit Debugger enabled
RB6 and RB7 are dedicated to the debugger
CFG_DEBUG_OFF In Circuit Debugger disabled
RB6 and RB7 are general purpose I/O pins
D
Data EEPROM code protect CFG_CPD_ON Data EEPROM is code protected
CFG_CPD_OFF Data EEPROM is not protected
E
Low Voltage In-Circuit Programming CFG_LVP_ON Low Voltage in-circuit serial Programming enabled
RB3/PGM pin has PGM function
CFG_LVP_OFF Low Voltage in-circuit serial Programming disabled
RB3/PGM pin has digital I/O function
(high voltage must be present on MCLR pin for programming)
F
Brown-Out Reset CFG_BODEN_ON Brown-Out Reset enabled
CFG_BODEN_OFF Brown-Out Reset disabled
G
Power-Up Timer CFG_PWRTE_ON power-up timer enable
CFG_PWRTE_OFF power-up timer disable
H
Watchdog timer CFG_WDT_ON watchdog timer enable
CFG_WDT_OFF watchdog timer disable
I
Oscillator CFG_RC_OSC Resistor / Capacitor (RC) oscillator
CFG_HS_OSC High Speed Crystal / Resonator (HS) oscillator
CFG_XT_OSC Crystal / Resonator (XT) oscillator
CFG_LP_OSC Low Power Crystal (LP) oscillator