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Diffstat (limited to 'firmware/libs-device/osccal.h')
| -rw-r--r-- | firmware/libs-device/osccal.h | 57 |
1 files changed, 0 insertions, 57 deletions
diff --git a/firmware/libs-device/osccal.h b/firmware/libs-device/osccal.h deleted file mode 100644 index af37a43..0000000 --- a/firmware/libs-device/osccal.h +++ /dev/null @@ -1,57 +0,0 @@ -/* Name: osccal.h - * Author: Christian Starkjohann - * Creation Date: 2008-04-10 - * Changes 2013-11-04 cpldcpu@gmail.com - * Tabsize: 4 - * Copyright: (c) 2008 by OBJECTIVE DEVELOPMENT Software GmbH - * License: GNU GPL v2 (see License.txt), GNU GPL v3 or proprietary (CommercialLicense.txt) - */ - -/* -General Description: -This module contains a function which calibrates the AVR's internal RC -oscillator so that the CPU runs at F_CPU (F_CPU is a macro which must be -defined when the module is compiled, best passed in the compiler command -line). The time reference is the USB frame clock of 1 kHz available -immediately after a USB RESET condition. Timing is done by counting CPU -cycles, so all interrupts must be disabled while the calibration runs. -The size optimized assembler implementation includes its own implementation -of usbMeasureFrameLength. Therefore USB_CFG_HAVE_MEASURE_FRAME_LENGTH should -be set to 0 to avoid including unused code sections. It is recommended to call -calibrateOscillatorASM() from the reset hook in usbconfig.h by including osccal.h: - -#include "osccal.h" - -This routine is an alternative to the continuous synchronization described -in osctune.h. - -Algorithm used: See osccalASM.x - -Limitations: -This calibration algorithm may try OSCCAL values of up to 192 even if the -optimum value is far below 192. It may therefore exceed the allowed clock -frequency of the CPU in low voltage designs! -Precision depends on the OSCCAL vs. frequency dependency of the oscillator. -Typical precision for an ATMega168 (derived from the OSCCAL vs. F_RC diagram -in the data sheet) should be in the range of 0.4%. Only the 12.8 MHz and -16.5 MHz versions of V-USB (with built-in receiver PLL) can tolerate this -deviation! All other frequency modules require at least 0.2% precision. -*/ - -#ifndef __OSCCAL_H_INCLUDED__ -#define __OSCCAL_H_INCLUDED__ - -#ifndef __ASSEMBLER__ - void calibrateOscillatorASM(void); -# define USB_RESET_HOOK(resetStarts) if(!resetStarts){ calibrateOscillatorASM();} -# define USB_CFG_HAVE_MEASURE_FRAME_LENGTH 0 -#endif -/* This function calibrates the RC oscillator so that the CPU runs at F_CPU. - * It MUST be called immediately after the end of a USB RESET condition! - * Disable all interrupts during the call! - * It is recommended that you store the resulting value in EEPROM so that a - * good guess value is available after the next reset. - */ - - -#endif /* __OSCCAL_H_INCLUDED__ */ |