diff --git a/ports/stm32f4/boards/STM32F411VETx_FLASH.ld b/ports/stm32f4/boards/STM32F411VETx_FLASH.ld
index a3c3594a94..763e7bcea9 100644
--- a/ports/stm32f4/boards/STM32F411VETx_FLASH.ld
+++ b/ports/stm32f4/boards/STM32F411VETx_FLASH.ld
@@ -62,7 +62,7 @@ _Min_Stack_Size = 0x400; /* required amount of stack */
 MEMORY
 {
 RAM (xrw)      : ORIGIN = 0x20000000, LENGTH = 128K
-FLASH (rx)      : ORIGIN = 0x8000000, LENGTH = 512K
+FLASH (rx)      : ORIGIN = 0x8000000, LENGTH = 512K - 256 - 100K
 }
 
 /* Define output sections */
diff --git a/ports/stm32f4/boards/stm32f411ve_discovery/mpconfigboard.h b/ports/stm32f4/boards/stm32f411ve_discovery/mpconfigboard.h
index 1bb5849afa..81e0f87901 100644
--- a/ports/stm32f4/boards/stm32f411ve_discovery/mpconfigboard.h
+++ b/ports/stm32f4/boards/stm32f411ve_discovery/mpconfigboard.h
@@ -30,8 +30,8 @@
 #define MICROPY_HW_BOARD_NAME       "STM32F411E_DISCO"
 #define MICROPY_HW_MCU_NAME         "STM32F411xE"
 
-// #define FLASH_SIZE                  (0x7D000)
-// #define FLASH_PAGE_SIZE             (0x4000)
+#define FLASH_SIZE                  (0x80000) //512K
+#define FLASH_PAGE_SIZE             (0x4000)  //16K
 
 #define CIRCUITPY_AUTORELOAD_DELAY_MS 500
 
diff --git a/ports/stm32f4/peripherals/stm32f4/stm32f411xe/clocks.c b/ports/stm32f4/peripherals/stm32f4/stm32f411xe/clocks.c
index f1ce6fef9f..6d2a6fac9a 100644
--- a/ports/stm32f4/peripherals/stm32f4/stm32f411xe/clocks.c
+++ b/ports/stm32f4/peripherals/stm32f4/stm32f411xe/clocks.c
@@ -57,5 +57,5 @@ void stm32f4_peripherals_clocks_init(void) {
   RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
   RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
   RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
-  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2);
+  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_3);
 }
diff --git a/ports/stm32f4/supervisor/internal_flash.c b/ports/stm32f4/supervisor/internal_flash.c
index fab0678182..70d9277e06 100644
--- a/ports/stm32f4/supervisor/internal_flash.c
+++ b/ports/stm32f4/supervisor/internal_flash.c
@@ -61,6 +61,7 @@ static const flash_layout_t flash_layout[] = {
     #endif
 };
 
+//Return the sector of a given flash address. 
 uint32_t flash_get_sector_info(uint32_t addr, uint32_t *start_addr, uint32_t *size) {
     if (addr >= flash_layout[0].base_address) {
         uint32_t sector_index = 0;
@@ -122,6 +123,7 @@ bool supervisor_flash_write_block(const uint8_t *src, uint32_t block) {
     int32_t dest = convert_block_to_flash_addr(block);
     if (dest == -1) {
         // bad block number
+        mp_printf(&mp_plat_print, "BAD FLASH BLOCK ERROR");
         return false;
     }
 
@@ -142,14 +144,25 @@ bool supervisor_flash_write_block(const uint8_t *src, uint32_t block) {
     if (HAL_FLASHEx_Erase(&EraseInitStruct, &SectorError) != HAL_OK) {
         // error occurred during sector erase
         HAL_FLASH_Lock(); // lock the flash
+        mp_printf(&mp_plat_print, "FLASH SECTOR ERASE ERROR");
         return false;
     }
 
+	__HAL_FLASH_DATA_CACHE_DISABLE();
+	__HAL_FLASH_INSTRUCTION_CACHE_DISABLE();
+
+	__HAL_FLASH_DATA_CACHE_RESET();
+	__HAL_FLASH_INSTRUCTION_CACHE_RESET();
+
+	__HAL_FLASH_INSTRUCTION_CACHE_ENABLE();
+	__HAL_FLASH_DATA_CACHE_ENABLE();
+
     // program the flash word by word
     for (int i = 0; i < (FILESYSTEM_BLOCK_SIZE / 4); i++) {
         if (HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, dest, *src) != HAL_OK) {
             // error occurred during flash write
             HAL_FLASH_Lock(); // lock the flash
+            mp_printf(&mp_plat_print, "FLASH WRITE ERROR");
             return false;
         }
         dest += 4;
diff --git a/ports/stm32f4/supervisor/internal_flash.h b/ports/stm32f4/supervisor/internal_flash.h
index 4d720913fd..434281ed56 100644
--- a/ports/stm32f4/supervisor/internal_flash.h
+++ b/ports/stm32f4/supervisor/internal_flash.h
@@ -46,7 +46,7 @@
 #define INTERNAL_FLASH_FILESYSTEM_START_ADDR ((STM32_FLASH_SIZE + STM32_FLASH_OFFSET) - INTERNAL_FLASH_FILESYSTEM_SIZE - CIRCUITPY_INTERNAL_NVM_SIZE)
 #define INTERNAL_FLASH_FILESYSTEM_NUM_BLOCKS (INTERNAL_FLASH_FILESYSTEM_SIZE / FILESYSTEM_BLOCK_SIZE)
 
-// #define INTERNAL_FLASH_SYSTICK_MASK     (0x1ff) // 512ms
-// #define INTERNAL_FLASH_IDLE_TICK(tick)  (((tick) & INTERNAL_FLASH_SYSTICK_MASK) == 2)
+#define INTERNAL_FLASH_SYSTICK_MASK     (0x1ff) // 512ms
+#define INTERNAL_FLASH_IDLE_TICK(tick)  (((tick) & INTERNAL_FLASH_SYSTICK_MASK) == 2)
 
 #endif  // MICROPY_INCLUDED_STM32F4_INTERNAL_FLASH_H