diff options
| author | Yuval Adam <yuv.adm@gmail.com> | 2014-06-29 12:34:32 +0300 |
|---|---|---|
| committer | Yuval Adam <yuv.adm@gmail.com> | 2014-06-29 12:34:32 +0300 |
| commit | c3e4c9a25c2910d2d66d52215b3406b13d5b23d5 (patch) | |
| tree | added370d1e356901f8579f076e3263fb0464db7 /boards/ek-tm4c123gxl/bitband/bitband.c | |
| parent | 990090a4cc9070837d31e66b58d40f0c3d038741 (diff) | |
Add more board models
Diffstat (limited to 'boards/ek-tm4c123gxl/bitband/bitband.c')
| -rw-r--r-- | boards/ek-tm4c123gxl/bitband/bitband.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/boards/ek-tm4c123gxl/bitband/bitband.c b/boards/ek-tm4c123gxl/bitband/bitband.c new file mode 100644 index 0000000..1b1d20e --- /dev/null +++ b/boards/ek-tm4c123gxl/bitband/bitband.c @@ -0,0 +1,262 @@ +//*****************************************************************************
+//
+// bitband.c - Bit-band manipulation example.
+//
+// Copyright (c) 2012-2014 Texas Instruments Incorporated. All rights reserved.
+// Software License Agreement
+//
+// Texas Instruments (TI) is supplying this software for use solely and
+// exclusively on TI's microcontroller products. The software is owned by
+// TI and/or its suppliers, and is protected under applicable copyright
+// laws. You may not combine this software with "viral" open-source
+// software in order to form a larger program.
+//
+// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
+// NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT
+// NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY
+// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
+// DAMAGES, FOR ANY REASON WHATSOEVER.
+//
+// This is part of revision 2.1.0.12573 of the EK-TM4C123GXL Firmware Package.
+//
+//*****************************************************************************
+
+#include <stdint.h>
+#include <stdbool.h>
+#include "inc/hw_memmap.h"
+#include "inc/hw_types.h"
+#include "driverlib/debug.h"
+#include "driverlib/gpio.h"
+#include "driverlib/fpu.h"
+#include "driverlib/pin_map.h"
+#include "driverlib/sysctl.h"
+#include "driverlib/systick.h"
+#include "driverlib/rom.h"
+#include "driverlib/uart.h"
+#include "utils/uartstdio.h"
+
+//*****************************************************************************
+//
+//! \addtogroup example_list
+//! <h1>Bit-Banding (bitband)</h1>
+//!
+//! This example application demonstrates the use of the bit-banding
+//! capabilities of the Cortex-M4F microprocessor. All of SRAM and all of the
+//! peripherals reside within bit-band regions, meaning that bit-banding
+//! operations can be applied to any of them. In this example, a variable in
+//! SRAM is set to a particular value one bit at a time using bit-banding
+//! operations (it would be more efficient to do a single non-bit-banded write;
+//! this simply demonstrates the operation of bit-banding).
+//
+//*****************************************************************************
+
+
+//*****************************************************************************
+//
+// The value that is to be modified via bit-banding.
+//
+//*****************************************************************************
+static volatile uint32_t g_ui32Value;
+
+//*****************************************************************************
+//
+// The error routine that is called if the driver library encounters an error.
+//
+//*****************************************************************************
+#ifdef DEBUG
+void
+__error__(char *pcFilename, uint32_t ui32Line)
+{
+ while(1)
+ {
+ //
+ // Hang on runtime error.
+ //
+ }
+}
+#endif
+
+//*****************************************************************************
+//
+// Delay for the specified number of seconds. Depending upon the current
+// SysTick value, the delay will be between N-1 and N seconds (i.e. N-1 full
+// seconds are guaranteed, along with the remainder of the current second).
+//
+//*****************************************************************************
+void
+Delay(uint32_t ui32Seconds)
+{
+ //
+ // Loop while there are more seconds to wait.
+ //
+ while(ui32Seconds--)
+ {
+ //
+ // Wait until the SysTick value is less than 1000.
+ //
+ while(ROM_SysTickValueGet() > 1000)
+ {
+ }
+
+ //
+ // Wait until the SysTick value is greater than 1000.
+ //
+ while(ROM_SysTickValueGet() < 1000)
+ {
+ }
+ }
+}
+
+//*****************************************************************************
+//
+// Configure the UART and its pins. This must be called before UARTprintf().
+//
+//*****************************************************************************
+void
+ConfigureUART(void)
+{
+ //
+ // Enable the GPIO Peripheral used by the UART.
+ //
+ ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
+
+ //
+ // Enable UART0
+ //
+ ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
+
+ //
+ // Configure GPIO Pins for UART mode.
+ //
+ ROM_GPIOPinConfigure(GPIO_PA0_U0RX);
+ ROM_GPIOPinConfigure(GPIO_PA1_U0TX);
+ ROM_GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);
+
+ //
+ // Use the internal 16MHz oscillator as the UART clock source.
+ //
+ UARTClockSourceSet(UART0_BASE, UART_CLOCK_PIOSC);
+
+ //
+ // Initialize the UART for console I/O.
+ //
+ UARTStdioConfig(0, 115200, 16000000);
+}
+
+//*****************************************************************************
+//
+// This example demonstrates the use of bit-banding to set individual bits
+// within a word of SRAM.
+//
+//*****************************************************************************
+int
+main(void)
+{
+ uint32_t ui32Errors, ui32Idx;
+
+ //
+ // Enable lazy stacking for interrupt handlers. This allows floating-point
+ // instructions to be used within interrupt handlers, but at the expense of
+ // extra stack usage.
+ //
+ ROM_FPULazyStackingEnable();
+
+ //
+ // Set the clocking to run directly from the crystal.
+ //
+ ROM_SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN |
+ SYSCTL_XTAL_16MHZ);
+
+ //
+ // Initialize the UART interface.
+ //
+ ConfigureUART();
+
+ UARTprintf("\033[2JBit banding...\n");
+
+ //
+ // Set up and enable the SysTick timer. It will be used as a reference
+ // for delay loops. The SysTick timer period will be set up for one
+ // second.
+ //
+ ROM_SysTickPeriodSet(ROM_SysCtlClockGet());
+ ROM_SysTickEnable();
+
+ //
+ // Set the value and error count to zero.
+ //
+ g_ui32Value = 0;
+ ui32Errors = 0;
+
+ //
+ // Print the initial value to the UART.
+ //
+ UARTprintf("\r%08x", g_ui32Value);
+
+ //
+ // Delay for 1 second.
+ //
+ Delay(1);
+
+ //
+ // Set the value to 0xdecafbad using bit band accesses to each individual
+ // bit.
+ //
+ for(ui32Idx = 0; ui32Idx < 32; ui32Idx++)
+ {
+ //
+ // Set this bit.
+ //
+ HWREGBITW(&g_ui32Value, 31 - ui32Idx) = (0xdecafbad >>
+ (31 - ui32Idx)) & 1;
+
+ //
+ // Print the current value to the UART.
+ //
+ UARTprintf("\r%08x", g_ui32Value);
+
+ //
+ // Delay for 1 second.
+ //
+ Delay(1);
+ }
+
+ //
+ // Make sure that the value is 0xdecafbad.
+ //
+ if(g_ui32Value != 0xdecafbad)
+ {
+ ui32Errors++;
+ }
+
+ //
+ // Make sure that the individual bits read back correctly.
+ //
+ for(ui32Idx = 0; ui32Idx < 32; ui32Idx++)
+ {
+ if(HWREGBITW(&g_ui32Value, ui32Idx) != ((0xdecafbad >> ui32Idx) & 1))
+ {
+ ui32Errors++;
+ }
+ }
+
+ //
+ // Print out the result.
+ //
+ if(ui32Errors)
+ {
+ UARTprintf("\nErrors!\n");
+ }
+ else
+ {
+ UARTprintf("\nSuccess!\n");
+ }
+
+ //
+ // Loop forever.
+ //
+ while(1)
+ {
+ }
+}
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