Christiaan A
STM32 blinky through bit banding
Fork of
mbed_blinky
by 
Mbed
Revision 10:3a480c091e52, committed 2016-01-27
- Comitter:
- crazyafrican
- Date:
- Wed Jan 27 02:48:46 2016 +0000
- Parent:
- 9:0d1a88e54782
- Commit message:
- Initial
Changed in this revision
| main.cpp | Show annotated file Show diff for this revision Revisions of this file |
| mbed.bld | Show annotated file Show diff for this revision Revisions of this file |
--- a/main.cpp Thu Oct 29 12:28:39 2015 +0000
+++ b/main.cpp Wed Jan 27 02:48:46 2016 +0000
@@ -1,12 +1,34 @@
#include "mbed.h"
+//{/*** Bit Banding *******************************************************/
+/* base address for bit banding */
+#define BITBAND_SRAM_REF (0x20000000)
+/* base address for bit banding */
+#define BITBAND_SRAM_BASE (0x22000000)
+/* base address for bit banding */
+#define BITBAND_PERIPH_REF (0x40000000)
+/* base address for bit banding */
+#define BITBAND_PERIPH_BASE (0x42000000)
+
+/* sram bit band */
+#define BITBAND_SRAM(address, bit) ((void*)(BITBAND_SRAM_BASE + (((uint32_t)address) - BITBAND_SRAM_REF) * 32 + (bit) * 4))
+
+/* periph bit band */
+#define BITBAND_PERIPH(address, bit) ((void*)(BITBAND_PERIPH_BASE + (((uint32_t)address) - BITBAND_PERIPH_REF) * 32 + (bit) * 4))
+//}/***********************************************************************/
+
+
+// Initialise LED1 gpio
DigitalOut myled(LED1);
+/* bit-band definition, LED1 is PA_5 */
+#define LED_BB *((volatile unsigned char *)BITBAND_PERIPH(&GPIOA->ODR, 5))
+
int main() {
while(1) {
- myled = 1;
+ LED_BB = 1; // set led on
wait(0.2);
- myled = 0;
+ LED_BB = 0; // clear led
wait(0.2);
}
}
--- a/mbed.bld Thu Oct 29 12:28:39 2015 +0000 +++ b/mbed.bld Wed Jan 27 02:48:46 2016 +0000 @@ -1,1 +1,1 @@ -http://mbed.org/users/mbed_official/code/mbed/builds/9296ab0bfc11 \ No newline at end of file +http://mbed.org/users/mbed_official/code/mbed/builds/4336505e4b1c \ No newline at end of file