openblt/Target/Demo/ARM7_LPC2000_Olimex_LPC_L22.../Boot/main.c

159 lines
6.3 KiB
C

/****************************************************************************************
| Description: bootloader application source file
| File Name: main.c
|
|----------------------------------------------------------------------------------------
| C O P Y R I G H T
|----------------------------------------------------------------------------------------
| Copyright (c) 2011 by Feaser http://www.feaser.com All rights reserved
|
|----------------------------------------------------------------------------------------
| L I C E N S E
|----------------------------------------------------------------------------------------
| This file is part of OpenBLT. OpenBLT is free software: you can redistribute it and/or
| modify it under the terms of the GNU General Public License as published by the Free
| Software Foundation, either version 3 of the License, or (at your option) any later
| version.
|
| OpenBLT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
| without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
| PURPOSE. See the GNU General Public License for more details.
|
| You should have received a copy of the GNU General Public License along with OpenBLT.
| If not, see <http://www.gnu.org/licenses/>.
|
| A special exception to the GPL is included to allow you to distribute a combined work
| that includes OpenBLT without being obliged to provide the source code for any
| proprietary components. The exception text is included at the bottom of the license
| file <license.html>.
|
****************************************************************************************/
/****************************************************************************************
* Include files
****************************************************************************************/
#include "boot.h" /* bootloader generic header */
#include "lpc2294.h" /* CPU register definitions */
/****************************************************************************************
* Function prototypes
****************************************************************************************/
static void Init(void);
/****************************************************************************************
** NAME: main
** PARAMETER: none
** RETURN VALUE: program return code
** DESCRIPTION: This is the entry point for the bootloader application and is called
** by the reset interrupt vector after the C-startup routines executed.
**
****************************************************************************************/
int main(void)
{
/* initialize the microcontroller */
Init();
/* initialize the bootloader */
BootInit();
/* start the infinite program loop */
while (1)
{
/* run the bootloader task */
BootTask();
}
/* program should never get here */
return 0;
} /*** end of main ***/
/****************************************************************************************
** NAME: Init
** PARAMETER: none
** RETURN VALUE: none
** DESCRIPTION: Initializes the microcontroller. The Fpll is set to 60MHz and Fvpb is
** configured equal to Fpll. The GPIO pin of the status LED is configured
** as digital output.
**
****************************************************************************************/
static void Init(void)
{
blt_int8u m_sel; /* pll multiplier register value */
blt_int8u pll_dividers[] = { 1, 2, 4, 8 }; /* possible pll dividers */
blt_int8u p_sel_cnt; /* loop counter to find p_sel */
blt_int32u f_cco; /* current controller oscillator */
/* check that pll multiplier value will be in the range 1..32 */
ASSERT_CT((BOOT_CPU_SYSTEM_SPEED_KHZ + ((BOOT_CPU_XTAL_SPEED_KHZ+1)/2)) / \
BOOT_CPU_XTAL_SPEED_KHZ >= 1);
ASSERT_CT((BOOT_CPU_SYSTEM_SPEED_KHZ + ((BOOT_CPU_XTAL_SPEED_KHZ+1)/2)) / \
BOOT_CPU_XTAL_SPEED_KHZ <= 32);
/* calculate MSEL: M = round(Fcclk / Fosc) */
m_sel = (BOOT_CPU_SYSTEM_SPEED_KHZ + ((BOOT_CPU_XTAL_SPEED_KHZ+1)/2)) / \
BOOT_CPU_XTAL_SPEED_KHZ;
/* value for the PLLCFG register is -1 */
m_sel--;
/* find PSEL value so that Fcco(= Fcclk * 2 * P) is in the 156000..320000 kHz range. */
for (p_sel_cnt=0; p_sel_cnt<sizeof(pll_dividers)/sizeof(pll_dividers[0]); p_sel_cnt++)
{
/* check f_cco with this pll divider */
f_cco = BOOT_CPU_SYSTEM_SPEED_KHZ * 2 * pll_dividers[p_sel_cnt];
if ( (f_cco >= 156000) && (f_cco <= 320000) )
{
/* found a valid pll divider value */
break;
}
}
/* check that a valid value was found */
ASSERT_RT(p_sel_cnt < (sizeof(pll_dividers)/sizeof(pll_dividers[0])));
/* set multiplier and divider values */
PLLCFG = (p_sel_cnt << 5) | m_sel;
PLLFEED = 0xAA;
PLLFEED = 0x55;
/* enable the PLL */
PLLCON = 0x1;
PLLFEED = 0xAA;
PLLFEED = 0x55;
/* wait for the PLL to lock to set frequency */
while(!(PLLSTAT & 0x400)) { ; }
/* connect the PLL as the clock source */
PLLCON = 0x3;
PLLFEED = 0xAA;
PLLFEED = 0x55;
/* enable MAM and set number of clocks used for Flash memory fetch. Recommended:
* Fcclk >= 60 MHz: 4 clock cycles
* Fcclk >= 40 MHz: 3 clock cycles
* Fcclk >= 20 MHz: 2 clock cycles
* Fcclk < 20 MHz: 1 clock cycle
*/
MAMCR = 0x0;
#if (BOOT_CPU_SYSTEM_SPEED_KHZ >= 60)
MAMTIM = 4;
#elif (BOOT_CPU_SYSTEM_SPEED_KHZ >= 40)
MAMTIM = 3;
#elif (BOOT_CPU_SYSTEM_SPEED_KHZ >= 20)
MAMTIM = 2;
#else
MAMTIM = 1;
#endif
MAMCR = 0x2;
/* setting peripheral Clock (pclk) to System Clock (cclk) */
VPBDIV = 0x1;
#if (BOOT_COM_UART_ENABLE > 0)
/* configure P0.0 for UART0 Tx and P0.1 for UART0 Rx functionality */
PINSEL0 |= 0x05;
#endif
#if (BOOT_COM_CAN_ENABLE > 0)
/* configure P0.25 for CAN1 Rx functionality */
PINSEL1 |= 0x00040000L;
#endif
} /*** end of Init ***/
/*********************************** end of main.c *************************************/