EBIKE-FreeRTOS/Common/drivers/Atmel/at91lib/boards/at91sam9xe-ek/board_lowlevel.c
2024-04-14 18:38:39 +08:00

195 lines
7.3 KiB
C

/* ----------------------------------------------------------------------------
* ATMEL Microcontroller Software Support
* ----------------------------------------------------------------------------
* Copyright (c) 2008, Atmel Corporation
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the disclaimer below.
*
* Atmel's name may not be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
* DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
* ----------------------------------------------------------------------------
*/
//------------------------------------------------------------------------------
// Headers
//------------------------------------------------------------------------------
#include "board.h"
#include "board_memories.h"
//------------------------------------------------------------------------------
// Local definitions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// \page "SAM9XE - Oscillator & PLL Parameters"
/// This page lists the parameters which are set for the PLL and main
/// oscillator configuration.
///
/// !Parameters
/// - BOARD_OSCOUNT
/// - BOARD_CKGR_PLLA
/// - BOARD_PLLACOUNT
/// - BOARD_MULA
/// - BOARD_DIVA
/// - BOARD_CKGR_PLLB
/// - BOARD_PLLBCOUNT
/// - BOARD_MULB
/// - BOARD_DIVB
/// - BOARD_USBDIV
/// - BOARD_PRESCALER
/// Main oscillator startup time (in number of slow clock ticks).
#define BOARD_OSCOUNT (AT91C_CKGR_OSCOUNT & (64 << 8))
/// PLLA frequency range.
#define BOARD_CKGR_PLLA (AT91C_CKGR_SRCA | AT91C_CKGR_OUTA_2)
/// PLLA startup time (in number of slow clock ticks).
#define BOARD_PLLACOUNT (63 << 8)
/// PLLA MUL value.
#define BOARD_MULA (AT91C_CKGR_MULA & (96 << 16))
/// PLLA DIV value.
#define BOARD_DIVA (AT91C_CKGR_DIVA & 9)
/// PLLB frequency range
#define BOARD_CKGR_PLLB AT91C_CKGR_OUTB_1
/// PLLB startup time (in number of slow clock ticks).
#define BOARD_PLLBCOUNT BOARD_PLLACOUNT
/// PLLB MUL value.
#define BOARD_MULB (124 << 16)
/// PLLB DIV value.
#define BOARD_DIVB 12
/// USB PLL divisor value to obtain a 48MHz clock.
#define BOARD_USBDIV AT91C_CKGR_USBDIV_2
/// Master clock prescaler value.
#define BOARD_PRESCALER AT91C_PMC_MDIV_2
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Local functions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// Default spurious interrupt handler
//------------------------------------------------------------------------------
void DefaultSpuriousHandler(void)
{
while (1);
}
//------------------------------------------------------------------------------
/// Default handler for fast interrupt requests.
//------------------------------------------------------------------------------
void DefaultFiqHandler(void)
{
while (1);
}
//------------------------------------------------------------------------------
/// Default handler for standard interrupt requests.
//------------------------------------------------------------------------------
void DefaultIrqHandler(void)
{
while (1);
}
//------------------------------------------------------------------------------
// Global functions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// Performs the low-level initialization of the chip.
//------------------------------------------------------------------------------
void LowLevelInit(void)
{
unsigned char i;
// Set flash wait states
//----------------------
AT91C_BASE_EFC->EFC_FMR = 6 << 8;
//#if !defined(sdram)
// Initialize main oscillator
//---------------------------
AT91C_BASE_PMC->PMC_MOR = BOARD_OSCOUNT | AT91C_CKGR_MOSCEN;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MOSCS));
// Initialize PLLA at 200MHz (198.656)
AT91C_BASE_PMC->PMC_PLLAR = BOARD_CKGR_PLLA
| BOARD_PLLACOUNT
| BOARD_MULA
| BOARD_DIVA;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCKA));
// Initialize PLLB for USB usage
AT91C_BASE_PMC->PMC_PLLBR = BOARD_USBDIV
| BOARD_CKGR_PLLB
| BOARD_PLLBCOUNT
| BOARD_MULB
| BOARD_DIVB;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCKB));
// Wait for the master clock if it was already initialized
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
// Switch to fast clock
//---------------------
// Switch to main oscillator + prescaler
AT91C_BASE_PMC->PMC_MCKR = BOARD_PRESCALER;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
// Switch to PLL + prescaler
AT91C_BASE_PMC->PMC_MCKR |= AT91C_PMC_CSS_PLLA_CLK;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
//#endif //#if !defined(sdram)
// Initialize AIC
//---------------
AT91C_BASE_AIC->AIC_IDCR = 0xFFFFFFFF;
AT91C_BASE_AIC->AIC_SVR[0] = (unsigned int) DefaultFiqHandler;
for (i = 1; i < 31; i++) {
AT91C_BASE_AIC->AIC_SVR[i] = (unsigned int) DefaultIrqHandler;
}
AT91C_BASE_AIC->AIC_SPU = (unsigned int) DefaultSpuriousHandler;
// Unstack nested interrupts
for (i = 0; i < 8 ; i++) {
AT91C_BASE_AIC->AIC_EOICR = 0;
}
// Watchdog initialization
//------------------------
AT91C_BASE_WDTC->WDTC_WDMR = AT91C_WDTC_WDDIS;
// Remap
//------
BOARD_RemapRam();
// Disable RTT and PIT interrupts (potential problem when program A
// configures RTT, then program B wants to use PIT only, interrupts
// from the RTT will still occur since they both use AT91C_ID_SYS)
AT91C_BASE_RTTC->RTTC_RTMR &= ~(AT91C_RTTC_ALMIEN | AT91C_RTTC_RTTINCIEN);
AT91C_BASE_PITC->PITC_PIMR &= ~AT91C_PITC_PITIEN;
}