185 lines
4.6 KiB
C
185 lines
4.6 KiB
C
/*
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* This file is part of the libopencm3 project.
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*
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* Copyright (C) 2012 Benjamin Vernoux <titanmkd@gmail.com>
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*
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* This library is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <libopencm3/lpc43xx/gpio.h>
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#include <libopencm3/lpc43xx/scu.h>
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#include <libopencm3/lpc43xx/cgu.h>
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#include <libopencm3/cm3/nvic.h>
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#include <libopencm3/lpc43xx/systick.h>
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#include <libopencm3/cm3/scs.h>
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#include "../jellybean_conf.h"
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/* Global counter incremented by SysTick Interrupt each millisecond */
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volatile u32 g_ulSysTickCount;
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u32 g_NbCyclePerSecond;
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void gpio_setup(void)
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{
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/* Configure all GPIO as Input (safe state) */
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GPIO0_DIR = 0;
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GPIO1_DIR = 0;
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GPIO2_DIR = 0;
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GPIO3_DIR = 0;
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GPIO4_DIR = 0;
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GPIO5_DIR = 0;
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GPIO6_DIR = 0;
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GPIO7_DIR = 0;
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/* Configure SCU Pin Mux as GPIO */
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scu_pinmux(SCU_PINMUX_LED1, SCU_GPIO_FAST);
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scu_pinmux(SCU_PINMUX_LED2, SCU_GPIO_FAST);
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scu_pinmux(SCU_PINMUX_LED3, SCU_GPIO_FAST);
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scu_pinmux(SCU_PINMUX_EN1V8, SCU_GPIO_FAST);
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scu_pinmux(SCU_PINMUX_BOOT0, SCU_GPIO_FAST);
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scu_pinmux(SCU_PINMUX_BOOT1, SCU_GPIO_FAST);
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scu_pinmux(SCU_PINMUX_BOOT2, SCU_GPIO_FAST);
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scu_pinmux(SCU_PINMUX_BOOT3, SCU_GPIO_FAST);
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/* Configure SSP1 Peripheral (to be moved later in SSP driver) */
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scu_pinmux(SCU_SSP1_MISO, (SCU_SSP_IO | SCU_CONF_FUNCTION5));
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scu_pinmux(SCU_SSP1_MOSI, (SCU_SSP_IO | SCU_CONF_FUNCTION5));
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scu_pinmux(SCU_SSP1_SCK, (SCU_SSP_IO | SCU_CONF_FUNCTION1));
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scu_pinmux(SCU_SSP1_SSEL, (SCU_SSP_IO | SCU_CONF_FUNCTION1));
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/* Configure GPIO as Output */
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GPIO2_DIR |= (PIN_LED1|PIN_LED2|PIN_LED3); /* Configure GPIO2[1/2/8] (P4_1/2 P6_12) as output. */
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GPIO3_DIR |= PIN_EN1V8; /* GPIO3[6] on P6_10 as output. */
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}
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void systick_setup(void)
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{
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u32 systick_reload_val;
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g_ulSysTickCount = 0;
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/* Disable IRQ globally */
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asm volatile ("cpsid i");
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/* Set processor Clock as Source Clock */
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systick_set_clocksource(STK_CTRL_CLKSOURCE);
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/* Get SysTick calibration value to obtain by default 1 tick = 10ms */
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systick_reload_val = systick_get_calib();
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/*
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* Calibration seems wrong on LPC43xx(TBC) for default Freq it assume System Clock is 12MHz but it is 12*8=96MHz
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* Fix the Calibration value bu multiplication by 8
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*/
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systick_reload_val = (systick_reload_val*8);
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/* To obtain 1ms per tick just divide by 10 the 10ms base tick and set the reload */
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systick_reload_val = systick_reload_val/10;
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systick_set_reload(systick_reload_val);
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systick_interrupt_enable();
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/* Start counting. */
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systick_counter_enable();
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/* Set SysTick Priority to maximum */
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nvic_set_priority(NVIC_SYSTICK_IRQ, 0xFF);
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/* Enable IRQ globally */
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asm volatile ("cpsie i");
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}
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void scs_dwt_cycle_counter_enabled(void)
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{
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SCS_DEMCR |= SCS_DEMCR_TRCENA;
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SCS_DWT_CTRL |= SCS_DWT_CTRL_CYCCNTENA;
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}
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u32 sys_tick_get_time_ms(void)
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{
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return g_ulSysTickCount;
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}
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u32 sys_tick_delta_time_ms(u32 start, u32 end)
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{
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#define MAX_T_U32 ((2^32)-1)
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u32 diff;
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if(end > start)
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{
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diff=end-start;
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}else
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{
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diff=MAX_T_U32-(start-end)+1;
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}
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return diff;
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}
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void sys_tick_wait_time_ms(u32 wait_ms)
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{
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u32 start, end;
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u32 tickms;
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start = sys_tick_get_time_ms();
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do
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{
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end = sys_tick_get_time_ms();
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tickms = sys_tick_delta_time_ms(start, end);
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}while(tickms < wait_ms);
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}
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/* Called each 1ms/1000Hz by interrupt
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1) Count the number of cycle per second.
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2) Increment g_ulSysTickCount counter.
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*/
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void sys_tick_handler(void)
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{
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if(g_ulSysTickCount==0)
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{
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/* Clear Cycle Counter*/
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SCS_DWT_CYCCNT = 0;
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}else if(g_ulSysTickCount==1000)
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{
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/* Capture number of cycle elapsed during 1 second */
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g_NbCyclePerSecond = SCS_DWT_CYCCNT;
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}
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g_ulSysTickCount++;
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}
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int main(void)
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{
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systick_setup();
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gpio_setup();
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/* SCS & Cycle Counter enabled (used to count number of cycles executed per second see g_NbCyclePerSecond */
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scs_dwt_cycle_counter_enabled();
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while (1)
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{
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gpio_set(PORT_LED1_3, (PIN_LED1|PIN_LED2|PIN_LED3)); /* LEDs on */
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sys_tick_wait_time_ms(500);
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gpio_clear(PORT_LED1_3, (PIN_LED1|PIN_LED2|PIN_LED3)); /* LED off */
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sys_tick_wait_time_ms(500);
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}
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return 0;
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}
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