diff --git a/include/libopencm3/stm32/comparator.h b/include/libopencm3/stm32/comparator.h
new file mode 100644
index 00000000..c1e49a94
--- /dev/null
+++ b/include/libopencm3/stm32/comparator.h
@@ -0,0 +1,25 @@
+/* This provides unification of code over STM32F subfamilies */
+
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * 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/>.
+ */
+
+#if defined(STM32F0)
+#       include <libopencm3/stm32/f0/comparator.h>
+#else
+#       error "stm32 family not defined."
+#endif
+
diff --git a/include/libopencm3/stm32/f0/comparator.h b/include/libopencm3/stm32/f0/comparator.h
new file mode 100644
index 00000000..a11fb372
--- /dev/null
+++ b/include/libopencm3/stm32/f0/comparator.h
@@ -0,0 +1,110 @@
+/** @defgroup comp_defines COMP Defines
+ *
+ * @brief <b>libopencm3 Defined Constants and Types for the STM32F0xx
+ * Comparator module</b>
+ *
+ * @ingroup STM32F0xx_defines
+ *
+ * @version 1.0.0
+ *
+ * @date 29 Jun 2013
+ *
+ *LGPL License Terms @ref lgpl_license
+ */
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2013 Frantisek Burian <BuFran@seznam.cz>
+ *
+ * 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/>.
+ */
+
+#ifndef LIBOPENCM3_COMP_H
+#define LIBOPENCM3_COMP_H
+
+#include <libopencm3/cm3/common.h>
+#include <libopencm3/stm32/memorymap.h>
+
+/* USART Registers ----------------------------------------------------------*/
+#define COMP1	0
+#define COMP2	1
+
+#define COMP_CSR(i)			MMIO16(SYSCFG_COMP_BASE + 0x1c + (i)*2)
+#define COMP_CSR1			COMP_CSR(COMP1)
+#define COMP_CSR2			COMP_CSR(COMP2)
+
+/* Register values ----------------------------------------------------------*/
+
+/* COMP_CSR Values ----------------------------------------------------------*/
+
+#define COMP_CSR_LOCK			(1 << 15)
+#define COMP_CSR_OUT			(1 << 14)
+
+#define COMP_CSR_HYST_SHIFT		12
+#define COMP_CSR_HYST			(3 << COMP_CSR_HYST_SHIFT)
+#define COMP_CSR_HYST_NO		(0 << COMP_CSR_HYST_SHIFT)
+#define COMP_CSR_HYST_LOW		(1 << COMP_CSR_HYST_SHIFT)
+#define COMP_CSR_HYST_MED		(2 << COMP_CSR_HYST_SHIFT)
+#define COMP_CSR_HYST_HIGH		(3 << COMP_CSR_HYST_SHIFT)
+
+#define COMP_CSR_POL			(1 << 11)
+
+#define COMP_CSR_OUTSEL_SHIFT		8
+#define COMP_CSR_OUTSEL			(7 << COMP_CSR_OUTSEL_SHIFT)
+#define COMP_CSR_OUTSEL_NONE		(0 << COMP_CSR_OUTSEL_SHIFT)
+#define COMP_CSR_OUTSEL_TIM1_BRK	(1 << COMP_CSR_OUTSEL_SHIFT)
+#define COMP_CSR_OUTSEL_TIM1_IC1	(2 << COMP_CSR_OUTSEL_SHIFT)
+#define COMP_CSR_OUTSEL_TIM1_OCRCLR	(3 << COMP_CSR_OUTSEL_SHIFT)
+#define COMP_CSR_OUTSEL_TIM2_IC4	(4 << COMP_CSR_OUTSEL_SHIFT)
+#define COMP_CSR_OUTSEL_TIM2_OCRCLR	(5 << COMP_CSR_OUTSEL_SHIFT)
+#define COMP_CSR_OUTSEL_TIM3_IC1	(6 << COMP_CSR_OUTSEL_SHIFT)
+#define COMP_CSR_OUTSEL_TIM3_OCRCLR	(7 << COMP_CSR_OUTSEL_SHIFT)
+
+#define COMP_CSR_WINDWEN		(1 << 23)
+
+#define COMP_CSR_INSEL_SHIFT		4
+#define COMP_CSR_INSEL			(7 << COMP_CSR_INSEL_SHIFT)
+#define COMP_CSR_INSEL_1_4_VREFINT	(0 << COMP_CSR_INSEL_SHIFT)
+#define COMP_CSR_INSEL_2_4_VREFINT	(1 << COMP_CSR_INSEL_SHIFT)
+#define COMP_CSR_INSEL_3_4_VREFINT	(2 << COMP_CSR_INSEL_SHIFT)
+#define COMP_CSR_INSEL_4_4_VREFINT	(3 << COMP_CSR_INSEL_SHIFT)
+#define COMP_CSR_INSEL_VREFINT		(3 << COMP_CSR_INSEL_SHIFT)
+#define COMP_CSR_INSEL_INM4		(4 << COMP_CSR_INSEL_SHIFT)
+#define COMP_CSR_INSEL_INM5		(5 << COMP_CSR_INSEL_SHIFT)
+#define COMP_CSR_INSEL_INM6		(6 << COMP_CSR_INSEL_SHIFT)
+
+#define COMP_CSR_SPEED_SHIFT		2
+#define COMP_CSR_SPEED			(3 << COMP_CSR_SPEED_SHIFT)
+#define COMP_CSR_SPEED_HIGH		(0 << COMP_CSR_SPEED_SHIFT)
+#define COMP_CSR_SPEED_MED		(1 << COMP_CSR_SPEED_SHIFT)
+#define COMP_CSR_SPEED_LOW		(2 << COMP_CSR_SPEED_SHIFT)
+#define COMP_CSR_SPEED_VERYLOW		(3 << COMP_CSR_SPEED_SHIFT)
+
+#define COMP_CSR_SW1			(1 << 1)
+#define COMP_CSR_EN			(1 << 0)
+
+/* API values ---------------------------------------------------------------*/
+
+BEGIN_DECLS
+
+void comp_enable(uint8_t id);
+void comp_disable(uint8_t id);
+void comp_select_input(uint8_t id, uint32_t input);
+void comp_select_output(uint8_t id, uint32_t output);
+void comp_select_hyst(uint8_t id, uint32_t hyst);
+void comp_select_speed(uint8_t id, uint32_t speed);
+
+END_DECLS
+
+#endif
diff --git a/lib/stm32/f0/Makefile b/lib/stm32/f0/Makefile
index b1040fd0..2e75aeec 100644
--- a/lib/stm32/f0/Makefile
+++ b/lib/stm32/f0/Makefile
@@ -33,7 +33,7 @@ CFLAGS		= -Os -g \
 
 ARFLAGS		= rcs
 
-OBJS		= flash.o rcc.o usart.o dma.o rtc.o
+OBJS		= flash.o rcc.o usart.o dma.o rtc.o comparator.o
 
 OBJS            += gpio_common_all.o gpio_common_f0234.o crc_common_all.o \
                    pwr_common_all.o iwdg_common_all.o rtc_common_l1f024.o \
diff --git a/lib/stm32/f0/comparator.c b/lib/stm32/f0/comparator.c
new file mode 100644
index 00000000..17fcab8f
--- /dev/null
+++ b/lib/stm32/f0/comparator.c
@@ -0,0 +1,61 @@
+/** @defgroup comp_file COMP
+ *
+ * @ingroup STM32F0xx
+ *
+ * @brief <b>libopencm3 STM32F0xx COMP</b>
+ *
+ * @version 1.0.0
+ *
+ * @date 10 July 2013
+ *
+ * LGPL License Terms @ref lgpl_license
+ */
+
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * 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/stm32/comparator.h>
+
+void comp_enable(uint8_t id)
+{
+	COMP_CSR(id) |= COMP_CSR_EN;
+}
+
+void comp_disable(uint8_t id)
+{
+	COMP_CSR(id) &= ~COMP_CSR_EN;
+}
+
+void comp_select_input(uint8_t id, uint32_t input)
+{
+	COMP_CSR(id) = (COMP_CSR(id) & ~COMP_CSR_INSEL) | input;
+}
+
+void comp_select_output(uint8_t id, uint32_t output)
+{
+	COMP_CSR(id) = (COMP_CSR(id) & ~COMP_CSR_OUTSEL) | output;
+}
+
+void comp_select_hyst(uint8_t id, uint32_t hyst)
+{
+	COMP_CSR(id) = (COMP_CSR(id) & ~COMP_CSR_HYST) | hyst;
+}
+
+void comp_select_speed(uint8_t id, uint32_t speed)
+{
+	COMP_CSR(id) = (COMP_CSR(id) & ~COMP_CSR_SPEED) | speed;
+}