AN4157

Peripheral firmware examples description

Doc ID 023629 Rev 1

9/24

3.6

EXTI example

3.6.1

Purpose

This example shows how to configure an external interrupt line.

3.6.2

Description

In this example:

●

PA0 pin is configured in input floating.

●

PA0 is configured to be used as an external interrupt source line 0 (EXTI0).

●

The EXTI line 0 is configured to generate an interrupt on each rising edge detected on

the PA0 pin. The interrupt is triggered every time the user push-button is pressed.

●

In the NVIC (nested vectored interrupt controller), the EXTI line 0 interrupt priority is

configured and the interrupt is enabled.

When the program is executed and the user push-button is pressed (EXTI0 interrupt

routine), LED4, LED6, LED9 and LED10 are toggled.

3.7

Flash program example

3.7.1

Purpose

This example describes how to program the STM32F30xor STM32F31x internal Flash

memory.

3.7.2

Description

In this example:

●

After Reset, the Flash memory Program/Erase Controller is locked. The

FLASH_Unlock function is used to unlock it.

●

Before programming the desired addresses, an erase operation is performed using the

Flash erase page feature. The erase procedure starts with the calculation of the

number of pages to be used. Then all these pages are erased one by one by calling

FLASH_ErasePage function.

●

Once this operation is finished, the programming operation is performed by using the

FLASH_ProgramWord function. The written data is then checked and the result of the

programming operation is stored into the MemoryProgramStatus variable.