Datasheet

DocID025083 Rev 7 19/121
STM32F303x6/x8 Functional overview
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3.7 General-purpose inputs/outputs (GPIOs)
Each of the GPIO pins can be configured by software as output (push-pull or open-drain), as
input (with or without pull-up or pull-down) or as peripheral alternate function. Most of the
GPIO pins are shared with digital or analog alternate functions. All GPIOs are high current
capable except for analog inputs.
The I/Os alternate function configuration can be locked if needed, following a specific
sequence to avoid spurious writing to the I/Os registers.
Fast I/O handling allows I/O toggling up to 36 MHz.
3.8 Direct memory access (DMA)
The flexible general-purpose DMA is able to manage memory-to-memory, peripheral-to-
memory and memory-to-peripheral transfers. The DMA controller supports circular buffer
management, avoiding the generation of interrupts when the controller reaches the end of
the buffer.
Each of the 7 DMA channels is connected to dedicated hardware DMA requests, with
software trigger support for each channel. Configuration is done by software and transfer
sizes between source and destination are independent.
The DMA can be used with the main peripherals: SPI, I
2
C, USART, general-purpose timers,
DAC and ADC.
3.9 Interrupts and events
3.9.1 Nested vectored interrupt controller (NVIC)
The STM32F303x6/8 devices embed a nested vectored interrupt controller (NVIC) able to
handle up to 60 interrupt channels that can be masked and 16 priority levels.
The NVIC benefits are the following:
• Closely coupled NVIC gives low latency interrupt processing
• Interrupt entry vector table address passed directly to the core
• Closely coupled NVIC core interface
• Allows early processing of interrupts
• Processing of late arriving higher priority interrupts
• Support for tail chaining
• Processor state automatically saved on interrupt entry and restored on interrupt exit
with no instruction overhead
The NVIC hardware block provides flexible interrupt management features with minimal
interrupt latency.
3.9.2 Extended interrupt/event controller (EXTI)
The external interrupt/event controller consists of 27 edge detector lines used to generate
interrupt/event requests and wake-up the system. Each line can be independently
configured to select the trigger event (rising edge, falling edge, both) and can be masked
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