diff --git a/docs/cd00283419-stm32f10xxx-flash-memory-microcontrollers-stmicroelectronics.pdf b/docs/cd00283419-stm32f10xxx-flash-memory-microcontrollers-stmicroelectronics.pdf
new file mode 100644
index 0000000..ecab753
Binary files /dev/null and b/docs/cd00283419-stm32f10xxx-flash-memory-microcontrollers-stmicroelectronics.pdf differ
diff --git a/src/drivers/flash.c b/src/drivers/flash.c
new file mode 100644
index 0000000..8b12e85
--- /dev/null
+++ b/src/drivers/flash.c
@@ -0,0 +1,77 @@
+//driver header
+#include "flash.h"
+
+//target header
+#include "../target/stm32f103xb.h"
+
+//custom header
+#include "../config.h"
+
+int unlock(void) {
+	FLASH->KEYR = FLASH_KEY1;
+	FLASH->KEYR = FLASH_KEY2;
+
+	if(FLASH->CR & (1<<7)) return -1;
+	return 0;
+}
+
+void lock(void) {
+	FLASH->CR |= 1<<7;
+}
+
+int flash_erase(uint16_t* page_addr) {
+	if(unlock()) return -1;
+
+	// check that flash is not busy
+	if(FLASH->SR & 1<<0) {
+		lock();
+		return -1;
+	}
+	
+	// select the page to erase
+	FLASH->CR |= 1<<1;
+	FLASH->AR = (uint32_t)page_addr;
+
+	// start erase
+	FLASH->CR |= 1<<6;
+
+	// wait for the operation to finish
+	while(FLASH->SR & 1<<0);
+	FLASH->CR &= ~(1<<1);
+	lock();
+
+	// check for errors
+	if(!(FLASH->SR & 1<<5)) return -1;
+	FLASH->SR |= 1<<5;
+
+	return 0;
+}
+
+int flash_write(uint16_t* addr, uint16_t* data, size_t data_len) {
+	if(unlock()) return -1;
+
+	// check that flash is not busy
+	if(FLASH->SR & 1<<0) return -1;
+
+	// write the flash
+	for(size_t i=0; i<data_len; ++i) {
+		FLASH->CR |= 1<<0;
+		addr[i] = data[i];
+		while(FLASH->SR & 1<<0);
+	}
+
+	// finish write operation
+	FLASH->CR &= ~(1<<0);
+	lock();
+
+	// check for errors
+	if(!(FLASH->SR & 1<<5)) return -1;
+	FLASH->SR |= 1<<5;
+
+	for(size_t i=0; i<data_len; ++i) {
+		if(addr[i] != data[i]) return -1;	
+	}
+
+	return 0;
+}
+
diff --git a/src/drivers/flash.h b/src/drivers/flash.h
new file mode 100644
index 0000000..538f605
--- /dev/null
+++ b/src/drivers/flash.h
@@ -0,0 +1,15 @@
+#ifndef FLASH_H
+#define FLASH_H
+
+//std headers
+#include <stdlib.h>
+#include <stdint.h>
+
+//------------------------------------------------------------------------------
+
+int flash_erase(uint16_t* page_addr);
+
+int flash_write(uint16_t* addr, uint16_t* data, size_t data_len);
+
+#endif
+
diff --git a/src/main.c b/src/main.c
index fffa31b..81fe91a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -5,6 +5,7 @@
 // driver includes
 #include "drivers/rcc.h"
 #include "drivers/io.h"
+#include "drivers/flash.h"
 
 Clock_t sysclks;
 #include "drivers/timer.h"
@@ -26,6 +27,14 @@ static void timeout_cb(void) {
 /* main function */
 int main(void) {
 
+	uint16_t* data_addr = (uint16_t*)0x8007C00; 
+	uint16_t data[8] = { 0x1234, 0x2345, 0x3456, 0x4567, 
+						 0x6789, 0x789A, 0x89AB, 0x9ABC };
+
+	if(flash_erase(data_addr)) return -1;
+	if(flash_write(data_addr, data, 4)) return -1;
+	if(flash_erase(data_addr)) return -1;
+
 	// configure clocks (necessary before using timers)
 	rcc_config_clock(CLOCK_CONFIG_PERFORMANCE, &sysclks);
 
@@ -35,15 +44,15 @@ int main(void) {
 	io_write(GPIOC, 1, PIN_13);
 
 	// start timed interruption
-	timer_tick_init(TIM2, 1000, timeout_cb);
+	timer_tick_init(TIM2, 2000, timeout_cb);
 	timer_start(TIM2);
 
-	uint32_t test = (uint32_t)(&end);
-	test++;
-	int* tab = (int*)malloc(10*sizeof(int));
-	for(int i=0; i<10; ++i) {
-		tab[i] = i;
-	}
+//	uint32_t test = (uint32_t)(&end);
+//	test++;
+//	int* tab = (int*)malloc(10*sizeof(int));
+//	for(int i=0; i<10; ++i) {
+//		tab[i] = i;
+//	}
 
 	// main loop
 	for(;;);