Microchip Technology XC8 Standard Compiler (Workstation) SW006021-1 SW006021-1 사용자 설명서
제품 코드
SW006021-1
MPLAB
®
XC8 C Compiler User’s Guide
DS52053B-page 196
2012 Microchip Technology Inc.
The psects used for storing these components are described in
Section 5.15.2 “Compiler-Generated Psects” and typically have a name based on
the initialism “bss” (Block Started by Symbol).
Section 5.15.2 “Compiler-Generated Psects” and typically have a name based on
the initialism “bss” (Block Started by Symbol).
The runtime startup code will clear all the memory location occupied by uninitialized
variables so they will contain zero before main() is executed.
variables so they will contain zero before main() is executed.
Variables whose contents should be preserved over a Reset should be qualified with
persistent
persistent
. See Section 5.4.8.1 “Persistent Type Qualifier” for more information.
Such variables are linked at a different area of memory and are not altered by the
runtime startup code in any way.
runtime startup code in any way.
If objects are initialized, the runtime startup code that performs this will destroy the con-
tents of the STATUS register. With some devices, the TO and PD bits in this register
are required to determine the cause of Reset. You can choose to have a copy of this
register taken so that it can later be examined. See Section 5.10.1.4 “STATUS Reg-
ister Preservation” for more information.
tents of the STATUS register. With some devices, the TO and PD bits in this register
are required to determine the cause of Reset. You can choose to have a copy of this
register taken so that it can later be examined. See Section 5.10.1.4 “STATUS Reg-
ister Preservation” for more information.
5.10.1.3
OSCILLATOR CALIBRATION
Some PIC devices come with an oscillator calibration constant which is pre-pro-
grammed into the device’s program memory. This constant can be written to the OSC-
CAL register to calibrate the internal RC oscillator, if required.
grammed into the device’s program memory. This constant can be written to the OSC-
CAL register to calibrate the internal RC oscillator, if required.
Code is automatically placed in the runtime startup code to load this calibration value,
see Section 5.3.9.1 “Oscillator Calibration Constants”.
see Section 5.3.9.1 “Oscillator Calibration Constants”.