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How does GPIO output Register on the stm32-electrical?
Hi I’m currently attempting to write a simple program using the STM32 Nucleo development board, based around the STM32F334R8. The application sets up the GPIO ports A and C and reads the state of the button. If the button is pressed, it turns on the LED. If not, it turns it off.
How to set GPIO pins in analog mode?
Few STM32 GPIO pins can be configured in analog mode which allows the use of ADC, DAC, OPAMP, and COMP internal peripherals. To use a GPIO pin in analog mode, the following register are considered: – GPIOx_MODER to select the mode (Input, Output, Alternate, Analog) – GPIOx_ASCR to select the required function ADC, DAC, OPAMP, or COMP
What are the problems with writing to GPIO registers?
The most obvious problem I see in your code is that you’re writing to the GPIO registers before enabling the clocks for the appropriate peripherals. Peripherals won’t respond correctly if their clocks haven’t been enabled. Enable all peripheral clocks before you try to do anything with the peripherals.
Which is faster Odr or bsrr for GPIO?
If you only need to change one bit, though, a single write to BSRR (or BRR) is faster, and uses less code space, than a read/modify/write cycle on ODR. However, if you actually do want to set the state of the whole port at once, or if you need to check the current output state, ODR is the way to go.
How many I / O pins does the STM32 use?
It allows the STM32 to communicate with logic supplied from 1.08 V, much lower than the VDD supply of the STM32, which can range up to 3.6 V. Up to 14 I/O pins in this domain can be used to communicate with other logic circuits which are supplied by voltage rails other than VDD.
Which is the atomic write register in STM32?
In case of GPIO configuration registers of STM32, we can perform atomic write operations using the dedicated BSRR and BRR registers. BSRR is a 32-bit register where the lower 16-bits are used to set any of the 16 pins and the higher 16-bits to clear/reset any of the 16 pins of a particular IO port.
How many registers are there in a GPIO port?
Each of the general-purpose I/O ports has two 32-bit configuration registers, two 32-bit data registers, a 32-bit set/reset register, a 16-bit reset register, and a 32-bit locking register. Each I/O port bit is freely programmable, however, the I/O port registers have to be accessed as 32-bit words (half-word or byte accesses are not allowed).