flash.c

DSP_UCOS_run_in_flash_nonBIOS

/**********************************************************************
* File: Flash.c
* Devices: TMS320F2833x
* Author: David M. Alter, Texas Instruments Inc.
* History:
*   12/18/07 - original (D. Alter)
**********************************************************************/
#include "DSP2833x_Device.h"			// Peripheral address definitions
#include "F28335_example.h"				// Main include file


/**********************************************************************
* Function: InitFlash()
* Description: Initializes the F2833x flash timing registers.
* Notes:
*  1) This function MUST be executed out of RAM.  Executing it out of
*     OTP/FLASH will produce unpredictable results.
*  2) The flash registers are code security module protected.  Therefore,
*     you must either run this function from secure RAM (L0/L1/L2/L3),
*     or you must first unlock the CSM.  Note that unlocking the CSM as
*     part of the program flow can compromise the code security.
* 3) The latest datasheet for the particular device of interest should
*    be consulted to confirm the flash timing specifications.
**********************************************************************/
#pragma CODE_SECTION(InitFlash, "secureRamFuncs")
void InitFlash(void)
{
	asm(" EALLOW");									// Enable EALLOW protected register access
	FlashRegs.FPWR.bit.PWR = 3;						// Pump and bank set to active mode
	FlashRegs.FSTATUS.bit.V3STAT = 1;				// Clear the 3VSTAT bit
	FlashRegs.FSTDBYWAIT.bit.STDBYWAIT = 0x01FF;	// Sleep to standby transition cycles
	FlashRegs.FACTIVEWAIT.bit.ACTIVEWAIT = 0x01FF;	// Standby to active transition cycles
	FlashRegs.FBANKWAIT.bit.RANDWAIT = 5;			// Random access waitstates
	FlashRegs.FBANKWAIT.bit.PAGEWAIT = 5;			// Paged access waitstates
	FlashRegs.FOTPWAIT.bit.OTPWAIT = 8;				// OTP waitstates
	FlashRegs.FOPT.bit.ENPIPE = 1;					// Enable the flash pipeline
	asm(" EDIS");									// Disable EALLOW protected register access

// Force a complete pipeline flush to ensure that the write to the last register
// configured occurs before returning.  Safest thing is to wait 8 full cycles.

    asm(" RPT #6 || NOP");

} // end of InitFlash()


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