Questions tagged [register]
A special, high-speed storage area within the CPU.
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Reset Value in Register with Multiplexer [closed]
I have a very simple circuit that looks like this:
Every time the clock is pulsed, the value in the register is incremented by 1. However, I want to use a multiplexer so that when ...
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How do I fix UUU output from modelsim testbench?
I am designing static Ram to be used with an add/sub on Quartus. I have created a block diagram and generated VHDL code. My schematic is correct but modelsim keeps giving me UUU for the output of my ...
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DDR_XCK register in atmega328
Page 166 of datasheet of atmega328 shows the use of a register called DDR_XCK.
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MSP430 ADC sampling does not work right
I am trying to get the 12bit ADC of the MSP430F5529 working.
For this reason I want to read values from its internal temperature sensor every 2 seconds. The ADC setup is in the main.c file and the ...
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How ideal should the clock input be for registers built out of 74HC chips?
I am a just starting my first build where a fully digital solution just isn't practical.
Basically I have an old laptop I want to give away but it doesn't have any backlight on the keyboard.
I have 2 ...
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Is there a circuit to detect if a line is high-impedance?
I was wondering if it was at all possible to detect a high-impedance state. I intend to use it with a LS245 within a register. It should essentially be able to turn on an LED (bring the output to HIGH)...
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What do the numbers in square brackets that come after the letters mean? AFRH15[3:0]. STM32 registers
The images show STM32 registers.
What do the numbers [1:0] after the name mean?
MODER15[1:0]
AFRH15[3:0]
The first digit is the number of bits if you start counting from zero.
What does the second ...
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How can I create variables like registers?
I'm currently working on a small home alarm system that runs on the PIC16F628A microcontroller. It's not the first time I came to a project with the idea of using my own custom created registers that ...
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LIS2DE12 accelerometer sleep-to-wake, wake-to-sleep configurations
I am having a difficult time understanding some of accelerometer register entries, what exactly I need to write to them and what do they mean.
To start with, I am trying to program LIS2DE12 ...
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FIFO buffer in the ATmega328P
I have a problem in understanding the working of the FIFO buffer. The diagram of the USART in the datasheet does not mention the FIFO buffer, and it just gives the UDR register which acts as a ...
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32-bit Mano Basic Computer structure
Reading Morris Mano's book about the basic computer, it mentions that the architecture used is 16-bit architecture, meaning the following registers have such lengths:
Address Register: 12-bits
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5:1 Mux design for a common bus system
I am tinkering with logic gates preparing for an exam and came across a question that states the following
Construct a common bus system for six registers where each register has five bits.
the ...
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Implementing FSM with Sequential Logic
I am trying to complete Problem 4 of this MIT Computation Structures lab, which requires you to use a circuit simulator called Jade to build a sequential logic circuit that implements the below FSM:
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Verilog: Changing a register or output depending on changes in multiple input signals
I am trying to output a 2 bit-number that indicates which input signal changed during the time span when "detection mode" is switched on by another input signal. The output is saved in a ...
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How does a flip-flop work in CPU registers?
From what I know, CPU registers work with flip-flops and when the data must pass from one register to another it travels on a bus. This happens only through an appropriate control signal.
What I want ...
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How do I handle interrupts manualy by registers in STM32?
I've just started learning STM32, and I'm learning it at low (register) level without libraries.
It is very easy to use GPIO: I #define memory addresses (like ...
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Ben Eater's 8-bit CPU: I can't get the register to load data on the bus
I am following Ben Eater's 8-bit computer series. I am currently working on the register. The clock is working fine. However, there are two issues:
When the data loads on the bus (for more detail, ...
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How can I improve this RAM implementation in VHDL?
I'm practicing for a lab exam and I'm trying to solve one from past years. I feel like I'm doing something wrong because I don't have much experience with VHDL.
Exam question
Write the VHDL code for ...
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How can I change ARR/CCRx register in ISR correctly?
I have strange behavior of timers. I'm using a Blue Pill with a STM32F103 chip with the HAL lib.
My case: I set up TIM2 to input capture mode to count impulses, then I store it in a global structure ...
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Can a register be considered a sequential circuit?
If you build a 2-bit register with JK flip-flops with the objective to allow storing the bit that was last added, can this be considered a sequential circuit?
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Analog ADC AD7134 / AD4134 Problem Writing/Reading Register
I am trying to configure the AD7134 in 4-Wire SPI Control Mode with an ESP32-S3. According to the documentation and Analog, the AD7134 and AD4134 are interchangeable with minimum differences. So I ...
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NINA-B30 series registers pdf
I want to know the register map/registers of the NINA-B30 series ICs, as I am used to writing low-level drivers on MCUs.
I could not find the datasheet that lists all the registers and their function ...
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How to get a reliable simulation of assignment delay in the always block (Xilinx Vivado)?
I am having trouble with simulation of the nonblocking assignment delay in the always block.
A simple example: assignment of the input ...
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Bistable memory cell with paired buffers instead of paired inverters
Bistable memory cells with paired inverters are very standard and basic building blocks (was used in Intel 8086 for example. ) But why not use paired buffers instead?
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Intel 8086 register bus default to high logic with pull-up resistor?
This schematic from righto.com's article on the register of 8086 shows a bi-stable latch with inverters.
When the read line is set to high, and the inverter output is also set to high, the bit line ...
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what's thsi register Address: "16’b11_0_1_0nnn_0001_0011" stands for?
I'm learning a "PHY full rate clock divider configuration register" and it represents its register Address as 16’b11_0_1_0nnn_0001_0011
I think 16 stands for bit number, ...
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A question about memory address in microcontroller vs PC [closed]
In context of embedded C, considering the following line:
*((volatile uint32_t *) 0x48000414) |= 1UL<<12;
Now 0x48000414 can be a memory pointer to a ...
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How do computer memories interact with each other (registers, cache, RAM, ROM)?
After Googling around for some time, I have managed to get a good understanding what makes these components different, but I've yet to find any clear computer architecture-focused article/thread on ...
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What is RCC in embedded C using registers? A register, or a pointer to a register, or something else?
Considering the following from here:
RCC->AHB1ENR
Is RCC above the register itself or pointer to a register. Because the -> operator is used with the ...
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STM32 bare-metal programming - Memory addressing in 32-bit system - memory offset
I am coming from a mechanical background and some Atmega experience, now doing some bare-metal programming courses on ARM processors. So far it is looking great, digging into documentation about uC ...
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STM32 UART Blocking Receiver Not Putting Data In Array, Overrun Flag
STM32F746 Disco, UART1 connected to ST-Link, Win 10, STM32CubeIDE, C, no HAL no other libraries other than CMSIS register definitions. Putty on Windows side to send and receive UART messages to/from ...
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How many times can a register bit be changed in AVR?
I am writing a program for an ATmega328P.
I have a while loop inside which I am enabling the UART receiver complete interrupt flag using the command ...
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PL011 write to DR when transmission disabled
The PL011 manual seems to assume that a TXE (transmission) is enabled when the CPU writes to DR:
It doesn't say what happens if the the transmission was disabled (bit 8 of control register is 0)
Is ...
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How to manipulate timer registers of Arduino Uno?
I already asked about How to achieve high speed microstepping? I even used Arduino Due to achieve high speed. Practically there was no difference compared to Uno but by changing baud rate I could see ...
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What is the cost of increasing the number of register names?
Increasing the number of registers in a CPU, has the upside that more values can be kept in registers instead of having to spill to stack. It has some downsides, one of which is that more instruction ...
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Will this register drawing work?
I have just learned about how logic gates work and I am trying to simulate a 1-bit register without using a clock signal. My design looks like this:
The logic should work something like this (...
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Computers: How signals in the bus can travel in either direction [closed]
I'm reading J. Clark Scott's book But How Do It Know.
When he is describing registers and the bus he illustrates this at one point as five registers sequentially parallel-connected to a bus.
As you ...
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STM32 timer output compare interrupt all interrupt flags set at once
I'm trying to set up the output compare channels of TIM3 of an STM32F103RB MCU.
For now I only enabled channel 1, but later I'll need CH2 and CH3 as well.
When CH1 triggers, the TIM3->SR register ...
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Making a register from DFFs without using multiplexers
I am currently trying to design a 4-bit register that is optimised in terms of transistor count, since I will be laying it out in a larger circuit that is very limited in terms of chip space. My ...
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How to Use Modular Arithmetic in Verilog
I am trying to code the RC6 (Rivest cipher 6) algorithm using Verilog. The algorithm requires addition, subtraction and multiplication in modulo 232. I've been told that I can use conventional +, -, * ...
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Shared rising edge detector? [closed]
Why do we have a rising edge detector in every flip flop of a register. Can't we just make a shared one for all the flip flops in order to save hardware?
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A transistor and a diode instead of a tri-state buffer
I was wondering if it is possible to replace the tri-state buffer with a transistor and a diode as shown in the image.
In this case a zero will be the same as high impedance. I don't understand why we ...
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Read data from a register in C-code [closed]
I am a beginner and learning by myself.
I need your help to start the third implementation in my life in VIVADO ( "Hello world" and "led")
I will implement SPI connection with DMA, ...
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What is the difference between register and memory?
I am currently studying the difference between microprocessors and microcontrollers and one of them says that:
Microprocessors have less number of registers, so more operations are memory based.
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Microcontroller bit information for the Core and different peripherals
Usually, from what I have seen, Microcontroller have this information of 8-bit, 16-bit and 32-bit.
In this Microcontroller S32K142, it is mentioned as 32-bit CPU. So, what does this actually mean?
I ...
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SPI frequency for slave and master?
I have been trying to hook up ADE7758 with STM32F401, but I am having a problem understanding the frequency part of it.
There is no minimum or maximum frequency for SPI CLK in the datasheet, and my ...
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What is the triangle symbol in circuit diagrams?
What is the triagular symbols shown in the image, is it a buffer or some kind of delay?
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How to make a register in VHDL remember?
I was given the assignment to implement an 18-bit register in VHDL. I used an example from the book "Free Range VHDL" recommended to me earlier. Here's what I got:
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Which type of registers is used in CPU: serial or parallel? And how to implement them in VHDL?
I'm making a CPU in which the memory is represented as a two-dimensional array, using FPGA. I've come to the implementation of registers, and I need the answer to this question. I'm new to electronics,...