GPIOs (general-purpose inputs/outputs)
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 in order to avoid spurious writing to the I/Os registers.
I/Os on APB2 with up to 18 MHz toggling speed
2.3.22
ADC (analog-to-digital converter)
Two 12-bit analog-to-digital converters are embedded into STM32F103xx performance line
devices and each ADC shares up to 16 external channels, performing conversions in single-
shot or scan modes. In scan mode, automatic conversion is performed on a selected group
of analog inputs.
Additional logic functions embedded in the ADC interface allow:
●
Simultaneous sample and hold
●
Interleaved sample and hold
●
Single shunt
The ADC can be served by the DMA controller.
An analog watchdog feature allows very precise monitoring of the converted voltage of one,
some or all selected channels. An interrupt is generated when the converted voltage is
outside the programmed thresholds.
The events generated by the general-purpose timers (TIMx) and the advanced-control timer
(TIM1) can be internally connected to the ADC start trigger, injection trigger, and DMA
trigger respectively, to allow the application to synchronize A/D conversion and timers.
2.3.23
Temperature sensor
The temperature sensor has to generate a voltage that varies linearly with temperature. The
conversion range is between 2 V < VDDA <
3.6 V. The temperature sensor is internally
connected to the ADC12_IN16 input channel which is used to convert the sensor output
voltage into a digital value.
2.3.24
Serial wire JTAG debug port (SWJ-DP)
The ARM SWJ-DP Interface is embedded. and is a combined JTAG and serial wire debug
port that enables either a serial wire debug or a JTAG probe to be connected to the target.
The JTAG TMS and TCK pins are shared with SWDIO and SWCLK, respectively, and a
specific sequence on the TMS pin is used to switch between JTAG-DP and SW-DP
