diff options
Diffstat (limited to 'boards/at91sam7l-vb/board_lowlevel.c')
| -rw-r--r-- | boards/at91sam7l-vb/board_lowlevel.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/boards/at91sam7l-vb/board_lowlevel.c b/boards/at91sam7l-vb/board_lowlevel.c new file mode 100644 index 0000000..b5f8810 --- /dev/null +++ b/boards/at91sam7l-vb/board_lowlevel.c @@ -0,0 +1,161 @@ +/* ----------------------------------------------------------------------------
+ * 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.
+ * ----------------------------------------------------------------------------
+ */
+
+//------------------------------------------------------------------------------
+/// \unit
+///
+/// !Purpose
+///
+/// Provides the low-level initialization function that gets called on chip
+/// startup.
+///
+/// !Usage
+///
+/// LowLevelInit() is called in #board_cstartup.S#.
+//------------------------------------------------------------------------------
+
+//------------------------------------------------------------------------------
+// Headers
+//------------------------------------------------------------------------------
+
+#include "board.h"
+#include "board_memories.h"
+
+//------------------------------------------------------------------------------
+// Internal definitions
+//------------------------------------------------------------------------------
+/// PLL frequency range.
+#define BOARD_CKGR_PLL AT91C_CKGR_OUT_2
+
+/// PLL startup time (in number of slow clock ticks).
+#define BOARD_PLLCOUNT AT91C_CKGR_PLLCOUNT
+
+/// PLL MUL value.
+#define BOARD_MUL (914 << 16)
+
+/// PLL DIV value.
+#define BOARD_DIV 1
+
+/// Master clock prescaler value.
+#define BOARD_PRESCALER 0
+
+//------------------------------------------------------------------------------
+// Internal functions
+//------------------------------------------------------------------------------
+//------------------------------------------------------------------------------
+/// Default spurious interrupt handler. Infinite loop.
+//------------------------------------------------------------------------------
+void defaultSpuriousHandler( void )
+{
+ while (1);
+}
+
+//------------------------------------------------------------------------------
+/// Default handler for fast interrupt requests. Infinite loop.
+//------------------------------------------------------------------------------
+void defaultFiqHandler( void )
+{
+ while (1);
+}
+
+//------------------------------------------------------------------------------
+/// Default handler for standard interrupt requests. Infinite loop.
+//------------------------------------------------------------------------------
+void defaultIrqHandler( void )
+{
+ while (1);
+}
+
+//------------------------------------------------------------------------------
+// Exported functions
+//------------------------------------------------------------------------------
+//------------------------------------------------------------------------------
+/// Performs the low-level initialization of the chip. This includes EFC, master
+/// clock, AIC & watchdog configuration, as well as memory remapping.
+//------------------------------------------------------------------------------
+void LowLevelInit( void )
+{
+ volatile unsigned int i;
+
+ // Set flash wait states in the EFC
+ // 48MHz = 1 wait state
+#if defined(at91sam7l64) || defined(at91sam7l128)
+ AT91C_BASE_MC->MC_FMR = AT91C_MC_FWS_3FWS;
+#else
+ #error No chip definition ?
+#endif
+
+ // Enable external oscillator (on first boot only, after that command does nothing)
+ gLowLevelInitSupcStatus = AT91C_BASE_SUPC->SUPC_SR;
+ if ((gLowLevelInitSupcStatus & AT91C_SUPC_OSCSEL) != AT91C_SUPC_OSCSEL) {
+
+ AT91C_BASE_SUPC->SUPC_CR = (0xA5 << 24) | AT91C_SUPC_XTALSEL;
+ while ((AT91C_BASE_SUPC->SUPC_SR & AT91C_SUPC_OSCSEL) != AT91C_SUPC_OSCSEL);
+ }
+
+ // Switch to slow clock if necessary (so PLL frequency can be changed)
+ if ((AT91C_BASE_PMC->PMC_MCKR & AT91C_PMC_CSS) == AT91C_PMC_CSS_PLL_CLK) {
+
+ AT91C_BASE_PMC->PMC_MCKR = AT91C_PMC_CSS_SLOW_CLK;
+ while ((AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY) != AT91C_PMC_MCKRDY);
+ }
+
+ // Initialize PLL at 30MHz
+ AT91C_BASE_PMC->PMC_PLLR = BOARD_CKGR_PLL | BOARD_PLLCOUNT | BOARD_MUL | BOARD_DIV;
+ while ((AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCK) == 0);
+
+ // Switch to PLL
+ AT91C_BASE_PMC->PMC_MCKR = AT91C_PMC_CSS_PLL_CLK;
+ while ((AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY) == 0);
+
+ // 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;
+ }
+
+ // Enable Debug mode
+ AT91C_BASE_AIC->AIC_DCR = AT91C_AIC_DCR_PROT;
+
+ // Watchdog initialization
+ AT91C_BASE_WDTC->WDTC_WDMR = AT91C_WDTC_WDDIS;
+
+ // Remap the internal SRAM at 0x0
+ BOARD_RemapRam();
+}
+
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