Questions tagged [assembly]

This is a programming language that is at a low level that corresponds with the instruction set of the machine being programmed.

Filter by
Sorted by
Tagged with
0
votes
1answer
98 views

PIC Microcontroller ADC not functioning

I coded an assembly script to take the input values from two LDRs in parallel. Then my microcontroller was supposed to convert this analogue input into an 8-bit digital value (omitting the 2 LSBs). ...
13
votes
3answers
15k views

What actually is a shadow register?

I noticed the term Shadow Register while going through a datasheet of a TMS320F28335 DSP. What does it actually mean? Does it have a physical location in the CPU as ...
3
votes
2answers
122 views

Back branches in code

While reading this file on software hazards this slide says: "No Back Branch in the Code" I wonder what does it mean? Normally when we write code in C-language then we don't actually do branching ...
1
vote
2answers
52 views

Load, then add in assembly

Im trying to load 2 values in assembly under the tm4c1294ntpcd (Cortex M4) then add it with the next code ...
1
vote
2answers
47 views

ATmega2560 I2C (TWI) assembler configuration problems

I am using ATmega2560 for testing an I2C code. I wrote subrutines in assembler for init, start, write, read and stop the I2C setup. The goal is that master writes 11110000 to a slave with address ...
-1
votes
3answers
91 views

Startup code in pure Assembly program [closed]

I came across some articles and books that saying when, I write in high-level language like C, startup code is used to prepare for my main code but when I write my program in pure Assembly there is no ...
1
vote
0answers
46 views

beq assembly MIPS

I'm so confused about beq function in assembly MIPS. Lets assume I have beq $t1 $t2 60 , so it would be mapped as I type function. so we could say for example ...
0
votes
1answer
96 views

Using pointer of a function's returned value

I would like to know if there are possibilities to change the following code: ...
1
vote
2answers
481 views

Why avr-as doesn't work?

I've got the following program, in AVR assembly: .DEF WR = R16 .ORG 0 SER WR OUT 0x24, WR When I call ...
1
vote
2answers
189 views

How to check whether a byte of 8 bits contains 1, assembler 8051?

I need to know how to check whether a byte contains a 1 for touch status in a MPR121 project, so if: 00000010 then pin 2 is touched 00000100 then pin 3 is touched How can I detect it? A ...
2
votes
2answers
59 views

Problem in Clock Gating Control with ARM Tiva C

When I access a peripheral register (such as a GPIO port) just after enabling the clock gating of the peripheral, a hard fault happens. For example: This code doesn't work (generates a hard fault): <...
0
votes
0answers
193 views

Branch offset out of range ARM assembly

So I tried compiling this code below but keep getting the 1176E error message of Branch offset out of range 0xFFFFFFE8 out of range permitted values are up to 0x00007E on the 5th code line. I ...
1
vote
3answers
122 views

How to look at the emitted assembly code of MPLAB X IDE

I'm using MPLAB X IDE V5.05 to generate the code to program a PIC32MX470F512L. It happens that i'm having some problems in the code and i would want to take a look ...
0
votes
1answer
355 views

PIC18F452 interfacing with HD44780 LCD in assembly

I have been trying to get a Hitachi HD44780 LCD to work with my PIC18F452 for a few days now, with no luck. I have tried moving the data lines to different ports on the microchip, I've tried ...
1
vote
1answer
79 views

Assembly language, accessing bytes of memory

I have some memory address 0x00000100 that I want to read from. The lower 4 bits read from this address indicates the states of 4 buttons - So bit 0 shows the state of button 0, bit 1 shows the state ...
0
votes
0answers
47 views

Is my assembly code in MIPS correct?

I've started studying assembly, and I'm trying to solve this problem: For the following C statement, what is the corresponding MIPS assembly code? Assume that the variables f, g, h, i, and j are ...
0
votes
1answer
60 views

Logisim input and terminal issue

I had this final gate that I made. but when I run it in terminal. it says my output is E instead of 0/1. I wanna know why my output is E instead of 0/1. The circuit should have four inputs: A, B, C, ...
3
votes
2answers
2k views

Why does __libc_init_array cause an exception?

After a long time trying to debug why my simple blinky code for my STM32F446RE microcontroller was not working i discovered a line in the bootup assembly file that i was linking to it which was ...
0
votes
1answer
34 views

Is Pull-up present by default?

I'm using the MC9S12DP512, Motorola's microcontroller. I was executing a service and ,at the end, I put low logic level at the pins PS4, PS5 and PS6, then after that, I configured these pins as inputs....
3
votes
1answer
128 views

As a computer science engineering graduate, do I need to learn Assembly language in today's day and age? [closed]

Given that there are simple and easy to learn/use MCU devices such as those offered by Arduino, Particle, TI (MSP430 series), Microchip (PIC16 series) does it make sense to teach ALP to computer ...
0
votes
0answers
63 views

Assembler program showing ACK even with the wrong slave address, I2C code problem!

I have this project communicating MPR121 capacitive touch sensing keyboard with 8051 microcontroller, with some references I've implemented some I2C code for serial communication between master and ...
1
vote
1answer
47 views

How to check the flow of assembler instructions execution?

I'm creating a project that uses I2C serial communication in assembler and I'm having some issues transmitting data and receiving back so I thought I should somehow debug the whole program, besides ...
0
votes
1answer
64 views

[Updated]How to select the values to move in assembler?

I'm trying to make the led blinks on the tm4c1294ncpdt, so the basic idea its to make 2 routines , one to select the GPIO port (in this case the F) and other to keep up on and off. the setup routine ...
2
votes
2answers
377 views

Unsigned 32-bit multiply in AVR assembly

How do I perform a multiplication by 2 of the unsigned 32-bit quantity in registers r18:r19:r20:r21 where r18 is the most ...
17
votes
4answers
3k views

What stops an assembly program from crashing the operating system? [closed]

First of all, I am a beginner, so if this question sounds silly, please point out the incorrect assumptions. From what I understand, the job of an operating system is to manage hardware and the ...
0
votes
1answer
148 views

TMOD value for timer 1 in mode 0 in 8051 microcontroller

What will be result of this statement: MOV TMOD,#00H Will it set it to timer 0 in mode 0 or to timer 1 in mode 0? Other statements like: ...
7
votes
1answer
614 views

What does [WEAK] mean in STM32 startup assembly code?

I was reading the STM32F407 startup file in Keil software to gather some information. I faced this problem: What is the [WEAK] symbol used for? A part of the code ...
6
votes
1answer
5k views

MIPS (PIC32): branch vs. branch likely

It's been a while since I've looked at the recent Microchip processors & I've been trying to learn a little bit about the PIC32 MIPS instruction set. I noticed there are two sets of branch ...
17
votes
3answers
16k views

Removing rosin flux residue from PCB

I have a nice looking purple PCB from Laen's batch service, which I have assembled using rosin flux. I have cleaned the board as best I can with isopropyl alcohol, which gets rid of the tackiness of ...
0
votes
1answer
102 views

What is the XTAL clock used for in an 8051 microntroller?

I'm trying to design an 8051 microcontroller circuit which uses timers/counters, and the circuit I'm using for inspiration uses a clock generated using the XTAL1 and XTAL2 pins of the IC, shown in the ...
0
votes
1answer
48 views

Built-in Timer Module HCS12

Why is it preferable to use the built-in timer module rather than using assembly language coding to create delay loops? I've gone through the entire "HCS12 Microcontroller and Embedded Systems" book,...
0
votes
1answer
49 views

Can you speed up debugging in Renesas High Performance Embedded Workshop by not flashing after breakpoint

I am debugging an H8S MCU in Renesas High Performance Embedded Workshop 4 with the attached E10A emulator, and find it's very slow when stepping through code because it keeps reflashing the chip ...
3
votes
2answers
248 views

Cortex M7 goes to HardFault immediately after reset

I am using the ATSAME70Q21 processor with a Cortex-M7 CPU. My development environment is Atmel Studio 7. I am using the SAME70 XPlained demo board. I am creating some code in assembly language. As ...
0
votes
1answer
91 views

.dw directive in AVR assembler

the piece of code below is mentioned in 8-bit AVR's instruction set as an example to explain the LPM instruction. ...
1
vote
2answers
421 views

24-bit two's complement division in AVR assembly

How do I perform a division by 2 of the 24-bit two's complement value in registers r6:r5:r4. (r6 is the most significant byte.) From what I have this is what I tried: ...
7
votes
1answer
2k views

How to produce a middle C on intel 8080?

This is a example problem in my book. Assuming pin 5 of port 4 is connected to an amplifier that drives a loudspeaker, the solution is given as, The frequency of middle C is $$f=261.63\ \text{Hz}$$ ...
1
vote
3answers
11k views

How to set all flags in 8085?

My Microprocessor teacher of 8085 gave an assignment to set all flags ! I have written this little program to set all except Sign, Please help me out ...
-1
votes
2answers
172 views

How do we find the bandwidth of a bus?

The data width and cycle rate are used to determine the bandwidth, or the total amount of data that the bus can transmit. An 8-bit bus (1-byte data width) that operates at a cycle rate of 1,000 MHz (1,...
-9
votes
2answers
99 views

DIP (dual inline package) [closed]

searching on the net, but couldnt understand for what is used DIP? Is it RAM? Will be glad for your answers.
1
vote
1answer
2k views

store word assembly instruction in risc-v

I'm really confused about the store instruction in risc-v. When I store word from register to memory, after the word is copied into the mem, does it sign-extended or zero-extended or perhaps something ...
3
votes
2answers
1k views

Why is my assembly code in MIPS wrong?

I've started studying assembly, and I've been tryign to solve this problem: For the following C statement, what is the corresponding MIPS assembly code? Assume that the variables f, g, h, i, and ...
5
votes
1answer
935 views

Effects of no-clean flux or RMA flux residue on signals

I keep on hearing that no-clean solder paste or flux is bad for analog or digital signals because it makes analog signals "noisy" and promotes cross talk on digital signals. Like this claim: Flux ...
0
votes
2answers
691 views

How to load immediate negative value in a register?

For example on 8-bit AVR given a register r16 I do something like ldi r16, 44 and this way I can give it positive values from 0 ...
3
votes
2answers
296 views

Understanding ARM instruction for numerical literal

I have done an instruction trace while trying to find a bug on a Cortex M3. There is one part of the command I cannot understand. STRB R1, [R3], #+0x01 According ...
1
vote
1answer
98 views

ATTiny414 inline assembly operand constraints for IO pin parameter

I'm trying to use the light_ws2812 library to drive WS2812 LEDs from an ATTiny414. The core of that library is an inline assembly snippet that bitbangs the serial line. here it is with the timing-nops ...
0
votes
3answers
183 views

Why do we need to declare ports as input/output?

I am writing code in assembly language (AT89s51). When I see a standard program, the ports are typically defined as inputs or outputs. But, without defining them it seems to work fine. How is this ...
0
votes
2answers
74 views

How a Computer Represents a Number Electronically

I understand how computers represent decimal numbers using binary. I have yet to absorb this video on how computers add numbers, which looks helpful. Before understanding that though, I would like to ...
1
vote
1answer
192 views

AVR-GCC initialization code

Consider the following asm.S .global main main: rjmp main Compile and dump it with these commands: ...
-4
votes
2answers
81 views

For the first prototype, how many pieces are necessary? Includes 256BGA, SMA, SDRAM

I'll most likely need to re-run. For the first batch of prototype, what is the safest number? Ordered 10pcs of PCBs and ordered 10x components.
0
votes
0answers
621 views

Servo motor interfacing with 8051 by assembly language

I know the principles of servo motor and programming it, I already done it with FPGA and adjusted the PWM like I wanted. But with 8051 assembly, I can't do the PWM or generate the 20 ms for the motors....