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Questions tagged [bus]

is a subsystem that transfers a plurality of digital bits grouped together to achieve or represent a common function or variable.

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59 views

Why do we need 'R_out' in 2-BUS arch?

Given some abstract architecture of CPU: Note that this CPU has 2-BUS. Why do we need the R_out and R_in? If I use Gra/Grb/Grc then obviousely I will need R_out. The Same for R_in when I use Sra/Srb/...
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58 views

Everything seems fine, but SPI Read/Write simply doesn't work. (Hardware-related)

Made a working breadboard Made a working protoboard Printed PCB - same exact schematic and code. Having issues. It appears to be just fine. The SS lines are working from the Pi all the way to the ...
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1answer
38 views

Pullup resistor operation between the ESP32 and a Bus MCU

I have an ESP32 as my main controller and a Bus. The bus operates where Pins 55 & 56 needs to be HIGH in order for the bus to be OFF. My ESP will drive the bus by enabling it by pulling those ...
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44 views

What is the fieldbus for Unitronics PLC?

I am currently investigating the inner behavior of a PLC of the brand Unitronics. I identified several bus for the communication with actuators, other PLCs, etc (like Modbus or CANbus) One thing I ...
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0answers
14 views

Isolation of SD IO pins during off state

I have a project at the moment that uses a PMOSFET to switch the supply to an SD card. According to the SanDisk SD datasheet available here: Because there are clamping diodes on the CMD, CLK, and ...
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0answers
19 views

CircuitStudio: How to connect zero-indexed buses to a repeat schematic sheet?

The general gist of what I'm trying to do (in CircuitStudio), is the following: In a hierarchical block "input", I generate four signals that are to be fed to an array of sensors, one signal per ...
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3answers
53 views

How should I drive a chip where I need to pull pins low in order to enable

I am wanting to use a FSTD16211 in my circuit. It's datasheet says that pins OE1 and OE2 should be high to disconnect the 2 channels of the bus, and both should be low to connect the 2 channels of the ...
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1answer
80 views

CAN bus with star configuration/long stubs

I am assisting in the development of a machine, and have been tasked with achieving high speed CAN (as close to 1 Mbit/s as possible) in a star configuration. The restrictions are: each arm is ...
2
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1answer
40 views

How would I place CAN termination resistors in a 3 ended configuration?

I have a project for which I have one central circuit board which has a can node on it, this central circuit board has three connectors on each of which a node could or could not be plugged in with a ...
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1answer
49 views

Should I take precautions when using different CAN transceivers on the same bus?

What are the precautions I should be aware of when using different transceivers on a CAN bus? What I can think of: They neeed to operate at the same voltage (on ...
1
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1answer
54 views

Ethernet connection using only one twisted pair

For my degree work, i make some reseaches for different bus systems and i've found ethernet a bit different than others: The old 10Base5 and 10Base2 ethernet used only one pair of conductor to ...
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1answer
44 views

J1708 (open collector RS485) at higher baud rates than 9600 bps?

I have here a PCB which has a kind of "open collector" RS-485, known as J1708 (schematic attached). The default baud rate is 9600 bps and there is no terminators, J1708-TX is a 3.3V signal. I would ...
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2answers
38 views

Price and process of rewiring a bus to run from solar power? [closed]

I want to rewire an omnibus from running off of gasoline to running off of solar panels. Not my field. What are some things that would have to be done? Specifically, what would it entail to ...
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3answers
88 views

Choosing best bus and protocol for ~128 clients over the wire

I am up to design system with ~128 MCUs communicating to one MCU master. Communication will be bidirectional. Data will be mostly sensor reads, but I plan to use the bus also as communication method ...
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0answers
88 views

design a modular system, choosing bus and backplane

Our team has developed a several controller boards for our current Projects for over three years. With little modifications we have used this board in several projects so far. Its structure is as ...
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2answers
85 views

Medium Range Two Wire Bus Recommendations?

Do you have any recommendations for a medium range (~10 meters) two-wire bus? My supply voltage is 24V and I'll have a single master with ~50 slaves connected to it. I've looked into: I2C - Great but ...
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2answers
84 views

I2C Single Master Multiple Slave

I have a one I2C master and 14 I2C slave devices connected on the bus. I want to clarify the order of things that happen on the I2C bus. Let say the master send an ADDRESS, then all the slave ...
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1answer
130 views

Splitting a bidirectional bus into two unidirectional ones

I am trying to sniff on a custom SPI-like bus protocol, which uses a unified bidirectional data line instead of separate MISO/MOSI. To make sense of the communication, I need to split it up into ...
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0answers
64 views

Sawtooth oscillations in bidirectional bus splitter [duplicate]

I am trying to listen in on a SPI-like protocol which is transferred on one busline in both directions (no slave-select). To discriminate which data is sent by which side, I need a bus splitter that ...
1
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1answer
66 views

Unnamed bus connections in schematics

I thought I could read schematics, but I have this problem: sometimes there are unnamed signals connected to buses and I don't know where they are supposed to be connected. Example: IC3 pis 14...23 ...
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2answers
91 views

I2C bus isolation for dummies

Consider you have two devices designed to be I2C masters in same bus. However, only one of them is operational at a time and the other one is completely powered down. In my case the devices have ...
2
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2answers
186 views

Multiple slaves with identical address on multi-master I2C bus [duplicate]

I'm planning a hardware design, where I have a main board and multiple peripheral boards. On each of these boards is a microcontroller with I2C, which is the communication bus for the boards. The same ...
2
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1answer
268 views

The CAN bus in this vehicle has only one 120 ohm termination resistance. What problems would this provoke?

This vehicle that I've started co-developing is designed with only a 120 termination resistor on the CAN bus. Obviously there should be two of those resistors on two ends of the bus. I will be making ...
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1answer
62 views

Microprocessor 8085 regains control of the bus

a) immediately after HOLD goes Low b) immediately after HOLD goes high c) after half clock cycle has passed once HLDS goes low d) after half clock cycle after HLDA goes high This question was asked ...
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1answer
71 views

How many external devices can be linked to a CPU with n address buses and m data buses?

(Hypothetical) Let's say there is a CPU with 8 address lines and 8 data lines. If each external device has 128 accessible registers, how many external devices can be linked? For 8 address lines, I ...
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28 views

Bidirectional data bus divided into nibbles not returning correct data - 8051

Since I have 10 I/O lines connected between two microcontrollers (AT89C4051 + AT89S52), I am trying to get away with elegant data transfer. Instead of spending months redoing an entire circuit board, ...
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1answer
40 views

Purpose of Bus Analyzer

I've not found the clear explanation for the WHY we use the bus analyzer except to capture and analyze data across the communication bus. Yes, we observe message structure, such as command words, ...
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1answer
71 views

What are the advantages of a wider bus in comparison to those of a higher clock frequency? [closed]

The aim is to increase data transfer rate. I understand each may have some drawbacks and advantages. Frankly I'm not knowledgeable enough to know of many so I'd like some input from others. I know ...
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2answers
104 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,...
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2answers
49 views

Address bus, databus: how much storage direct accessible

I have a CPU with a 32 bits data bus and a 21 bits address bus. I would like to know how much storage I can connect to this CPU directly. Does this depend on the address bus width, because I can ...
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1answer
110 views

Unused bits on a DDR3 chip

I have 2 DDR3 x16 chips (MT41K256M16xx) interfaced with an FPGA (M2S150TS-1FCS536). I plan on using point-to-point data & fly-by address/command topologies. I'm using ECC with a 16 bit bus, so 18 ...
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3answers
655 views

How does the AXI-Interconnect know where to route the data?

Im interested in where exactly the Addresses (BASE_ADDR) set in the "Address Editor" of a Vivado Block Design come into play in the FPGA-Part. I have multiple Blocks with AXI-Lite connected to a Zynq ...
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2answers
87 views

Are memory-mapped registers actually implemented as real registers?

I am currently trying to better understand microcontroller-architectures and I am particularly studying the ARM cortex-m3 right now. What I have always wondered is, if memory mapped registers are ...
4
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1answer
331 views

KiCad Bus on multiple sheets - Are labels the right way to go?

I want to connect bus-lines via several-sheets in KiCAD 5.0 But I don't know whether I got that right. Please consider the following design: Shown in Figure 1 you can see my connection from the chips ...
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3answers
205 views

Multiple I²C slaves with different addresses VS. using a multiplexer

I'd like to interface a lot of identical I²C sensors, let's say 32, with a MCU that has only 2 I²C busses. I can configure each sensor to have up to 8 different addresses. Hence I can have 8 sensors ...
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4answers
450 views

CAN Bus on PCB board

Will a CAN bus also work for on-board communication, without twisted pair cabling, between 2 or more microcontrollers on the same PCB board?
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3answers
1k views

Sampling rate understanding for ADC requirement

So I have this voltage plot. These are voltages corresponding to a current changes on a wire. I am trying to understand the rate of transmission for choosing a ADC to read these analog values. The ...
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0answers
29 views

LTspice modelling for the end terminal side

So I have this model. I am trying to build a current/voltage converter circuit for a bus carrying current to the other end of the bus, because I need to give this voltage output from the amplifier to ...
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0answers
34 views

Multi-channel data transmission system for Pixhawk autopilot

I hope to connect multiple Pixhawk autopilots to one PC, to establish a simulation system. In case you are unfamiliar with Pixhawk autopilot, here is a brief introduction: Pixhawk autopilot is an ...
2
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1answer
181 views

Terminator in Raspberry Pi CAN-shield

I am planning to connect (at least) two Raspberry Pi + PiCAN2 shields via CAN. I think I understand the concept of a daisy-chained multidrop CAN line, but what about using the 120 ohm resistors for ...
0
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1answer
91 views

wide parallel bus

I need to implement a custom 64-bit wide parallel bus interface operating at 100MHz (800MB/s total bandwidth). While there are no ready solutions for this, is it possible to implement such bus by ...
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0answers
58 views

Propagate data bits with 8 BIT register in ISE SR8RLED

I had some issues propagating the input from the 8 BIT register to the output using the SR8RLED 8 BIT Register in Xilinx ISE. The register has the following parameters: ...
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1answer
146 views

MAG3110 and MPU6050 on one I2C bus connected to a Raspberry Pi

I am trying to use separate pre-built breakout modules containing a MAG3110 (Magnetometer) (module) and a MPU6050 (gyroscope) (GY-521 module) on one I2C bus connected to a Raspberry Pi. Although both ...
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2answers
125 views

Bus tapping in Xilinx ISE for 8 bit to 16 bit conversion

I have a processing unit which is controlled by a sequencer/control unit. The agenda of this processing unit is to multiply 2 numbers using 8 BIT registers using the bit shift and add method. Once ...
2
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1answer
206 views

Altium buses between sheets on a flat design

I have a really big design to do and I'm having a rough time with buses. I have several doubts I hope someone can help me solve. Can I take a bus between sheets using an Off-Sheet Connector? For ...
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2answers
93 views

How best to interface with this bus switch from an ESP32

I am wondering how to interface with this bus switch from a ESP32. I need to drive OE1 and OE2 LOW at 5v , see datasheet I know that I can only drive up to 3.3v from the ESP32 directly, so is there ...
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3answers
98 views

Store more than 4 bit data on 8 bit bus

I don't have electrical background, but yesterday after watching some videos on youtube about old 8 bit computer, I have some question about how they work. 8 bit computer has 8 bit bus data which ...
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1answer
78 views

How to prevent SOIC8 clip from backfeeding

I'm trying to read the flash ROM using a SOIC8 clip, on board. I am horrible at surface mount soldering. Is there a way to use the clip on the board, without removing the chip, and not have the SOIC8 &...
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3answers
1k views

Looking for a device to “pass through” or “make high impedance” 8 bits based on one control bit

I need a thing (preferably a single IC) that has 8-bit input, 8-bit output and a control bit, with this behaviour: If the control bit is active, set output bits to the inputs (no need to actually ...
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1answer
2k views

Multiple CAN bus devices broadcasting at the same time…possible conflict?

I've worked with CAN bus recently and started to wonder what would happen if multiple devices on a network suddenly happen to broadcast at the same time. I mean every device on the CAN-bus network ...