Work on scs.h register and also nvic.h.

ARM Interrupt API (see nvic.h).
ARM SysTick API (see systick.h).
Example using both Interrupt and SysTick and blink LED1/2/3 see systickdemo.c.

lib/lpc43xx/Makefile

@@ -31,7 +31,7 @@ CFLAGS		= -O2 -g -Wall -Wextra -I../../include -fno-common \
 		  -mfloat-abi=hard -mfpu=fpv4-sp-d16
 # ARFLAGS	= rcsv
 ARFLAGS		= rcs
-OBJS		= gpio.o vector.o scu.o i2c.o ssp.o
+OBJS		= gpio.o vector.o scu.o i2c.o ssp.o nvic.o systick.o
 
 # VPATH += ../usb
 

lib/lpc43xx/nvic.c

@@ -0,0 +1,76 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
+ * Copyright (C) 2012 Fergus Noble <fergusnoble@gmail.com>
+ * Copyright (C) 2012 Benjamin Vernoux <titanmkd@gmail.com>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <libopencm3/cm3/scs.h>
+#include <libopencm3/lpc43xx/nvic.h>
+
+void nvic_enable_irq(u8 irqn)
+{
+	NVIC_ISER(irqn / 32) = (1 << (irqn % 32));
+}
+
+void nvic_disable_irq(u8 irqn)
+{
+	NVIC_ICER(irqn / 32) = (1 << (irqn % 32));
+}
+
+u8 nvic_get_pending_irq(u8 irqn)
+{
+	return NVIC_ISPR(irqn / 32) & (1 << (irqn % 32)) ? 1 : 0;
+}
+
+void nvic_set_pending_irq(u8 irqn)
+{
+	NVIC_ISPR(irqn / 32) = (1 << (irqn % 32));
+}
+
+void nvic_clear_pending_irq(u8 irqn)
+{
+	NVIC_ICPR(irqn / 32) = (1 << (irqn % 32));
+}
+
+u8 nvic_get_active_irq(u8 irqn)
+{
+	return NVIC_IABR(irqn / 32) & (1 << (irqn % 32)) ? 1 : 0;
+}
+
+u8 nvic_get_irq_enabled(u8 irqn)
+{
+	return NVIC_ISER(irqn / 32) & (1 << (irqn % 32)) ? 1 : 0;
+}
+
+void nvic_set_priority(u8 irqn, u8 priority)
+{
+	if(irqn>NVIC_M4_QEI_IRQ)
+	{
+		/* Cortex-M  system interrupts */
+		SCS_SHPR( (irqn&0xF)-4 ) = priority;
+	}else
+	{
+		/* Device specific interrupts */
+		NVIC_IPR(irqn) = priority;
+	}
+}
+
+void nvic_generate_software_interrupt(u8 irqn)
+{
+	if (irqn <= 239)
+		NVIC_STIR |= irqn;
+}

lib/lpc43xx/systick.c

@@ -0,0 +1,69 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
+ * Copyright (C) 2012 Benjamin Vernoux <titanmkd@gmail.com>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <libopencm3/lpc43xx/systick.h>
+
+void systick_set_reload(u32 value)
+{
+	STK_LOAD = (value & 0x00FFFFFF);
+}
+
+u32 systick_get_value(void)
+{
+	return STK_VAL;
+}
+
+void systick_set_clocksource(u8 clocksource)
+{
+	STK_CTRL |= clocksource;
+}
+
+void systick_interrupt_enable(void)
+{
+	STK_CTRL |= STK_CTRL_TICKINT;
+}
+
+void systick_interrupt_disable(void)
+{
+	STK_CTRL &= ~STK_CTRL_TICKINT;
+}
+
+void systick_counter_enable(void)
+{
+	STK_CTRL |= STK_CTRL_ENABLE;
+}
+
+void systick_counter_disable(void)
+{
+	STK_CTRL &= ~STK_CTRL_ENABLE;
+}
+
+u8 systick_get_countflag(void)
+{
+	if (STK_CTRL & STK_CTRL_COUNTFLAG)
+		return 1;
+	else
+		return 0;
+}
+
+u32 systick_get_calib(void)
+{
+	return (STK_CALIB&0x00FFFFFF);
+}