Category: Zynq spi example code

For this tutorial I am using Vivado This will bring up the IP configuration window. Wire them up to the corresponding pin on the SPI controller. Note: there will be many unused pins, since the controller can be used as a master, slave, or both. To do this, instantiate a constant IP module and set the value to 1.

My block design is shown below:. Note that I have also marked the pins for debug. This can be really useful for debugging your software using the embedded logic analyzer feature of Vivado. Generate a bitstream and export your design to SDK. You need to create a PetaLinux project and extract the hardware description from your project SDK directory as discussed in tutorial Before you build PetaLinux, though, you need to modify the device tree to create the appropriate device file for your SPI device.

Then you need to enable SPI support for your kernel. To configure the kernel run the following command. Now you can run petalinux-build and petalinux-package to build and package Linux. Then copy the program to your board using ssh. Run the command, and if you use the embedded logic analyzer, you should see activity on the SPI interface. Will the block design in vivado be the same as given in this tutorial?

How can i get my fpga to control the LMXevm? The constraints and PS configuration will differ depending on how you are connecting the device to the board. How can I get hold of a copy of system-top.Asked by RichardV. There must be another file that has this board information.

I'm calling this an " invisible constraint file ". Do I use the actual constraint file to set my SPI port pin assignments for my second port? If so, wouldn't that "invisible constraint file" interfere? Are there any SPI examples with multiple slaves to demonstrate this? Hi RichardV. Thank you for pointing out the PMOD port, which is accessible.

Hello one last time on this subject Jon. I just visited the repository with that SF3 example. The whole project is in pieces.

I see multiple version of constraint files, and I don't see a Vivado project anywhere. I don't understand how to use this repository too.

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It's not like Github. What does "Pull" mean? How do I download a project as a complete entity that I don't have to reconstruct? I visited that repository "Boot Camp", but it also isn't very clear. Sorry about not including this. Hello again Jon. I am trying to follow along with the PmodSF3 example. Unfortunately my block does not validate because I have all of these port input pins left open warnings. I cannot synthesize my design, even though the Validate function show only warnings.

There is no example explaining what ports need to be connected.In this interface, in addition to transmit and receive lines, there is a third line that is used for clock line. Each slave device also has a chip select enable pin, that is used for activating the device.

SPI communication is different from other serial communication especially on data transfer. There is no concept like transmit and receive data, but there is a data trading concept. When data trading occurs, the data bits in master register is traded with the data bits in slave register on every clock from master one data bit per clock tick. You can think SPI is like shift registers.

There are 2 shift registers, one in master device and another in slave device. The figure above illustrates the bit trading from master to slave. Master register contain data 0xFF and slave register contain data 0x After one clock tick, the master is left with seven of its original bits and the first one that is come in from the slave, and vice versa.

After a total of eight clock ticks, all eight bits of each byte have traded place. Sometimes not all data byte come from slave or sent to slave is meaningful. This happen because probably slave device has not received any command yet, so the data in slave register is not meaningful. The figure above is the timing diagram of SPI protocol.

We know that to communicate to the slave device, the slave select pin should be activated active low.

SPI Controller C Code Example

The data is sampled every rising edge of clock. We can also sample data on falling edge of clock, this setting can be configured depending on the feature of the hardware SPI that you use.

In this example, master is send data byte 0x53 to slave and then slave send data byte 0x46 to master. This is the Arduino code for SPI slave device. You can get the project file from here. This is the result:. Go to the part 6 of the tutorial. Your email address will not be published.

All source codes included. SPI slave Arduino.ADC waveforms. Downloading overlays. Grove ADC. Arduino analog example. OpenCV software filters. Grove LED bar. Creating new overlays. OpenCV face detection. Timer example. PYNQ audio.

PWM example. USB webcam. Shell commands. Temperature sensor. USB Wifi. Example Notebooks. A selection of notebook examples are shown below that are included in the PYNQ image.

The notebooks contain live code, and generated output from the code can be saved in the notebook. PYNQ Community. Tutorials and other resources. FPGA-based neural network inference project.Each controller can generate three independent SS signals and seven different interrupts, and each controller has its own set of control and status registers shown in the table below.

zynq spi example code

Transmit data can be written into the FIFO much faster than it can be sent out, so if you write more than bytes, you must manage the transmit FIFO by polling status bits or setting up interrupts. Data arriving in the receive FIFO can be read after checking status bits to confirm new data is available or in response to an interrupt. The tables below show the status bits that are available in the status register, and the available interrupt sources. The SPI controller input clock is fixed at A mandatory programmable clock divider is applied to the input clock to divide it to a lower value.

Bits in the SPI Configuration Register define the clock divider value according to the formula: As an example, setting bits to will divide This can be accomplished by writting the specific value 0xDF0D to the unlock register address 0xF After a small delay, you can clear the bits and the reset of the SPI modules will be complete.

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Now you should relock the SLCRs for security. If manual CS is enabled, the module will drive the configured CS even when no transaction is on the SPI bus the CS lines will reflect the value in the control register. The module also supports using an external decoder to support more than 3 CS lines. If decoder support is enabled more than 1 CS line can be driven at once, if the option is disabled only a single line can be driven at a time.

zynq spi example code

If the external decoder is enabled, the CS lines will reflect the state of bitsbit 13 must be set high. If the external decoder is disabled, the lowest CS bit set to zero is prioritized CS0 has the highest priorty, CS2 has the lowest.

The configuration of the SPI module may need to be different for communication with different devices. The configuration covered below is recommended for communication with the inertial module on the Blackboard. The baudrate divider for the SPI clock only divides powers of 2. So a working value you can put in the bitfield is 4. The remaining fields in the control register control the chip-select lines as well as configure how SPI transactions are started.

The accelerometer and gyroscope are selected via CS0 and the magnetometer is selected with CS1. These lines are not connected through a decoder, so the external decoder bit CR, bit 9 should be clear making the chip selects mutually exclusive. For convenience, the chip select mode can be set to automatic by clearing bit 1 in the CR; If auto-CS is enabled, the chip select will only drive when an SPI transaction is active. Before you start a transaction, set the CS field in the control register bits to the appropriate value for the slave device you want.

The magnetometer is activated with CS1. Make sure you set the slave select value of the device you want in the control regsiter before you begin a transaction. If the manual start enable bit bit 15 is set in the control register, transfers will begin after the manual start bit bit 16 in the register is set.

If the manual start enable bit is clear, the module will automatically start transfers when there is at least one byte in the transmit FIFO. On Zynq, if you wish to receive a number of bytes, you must put that many bytes in the transmit FIFO first.

The actual communication sequence via SPI can differ from device to device. The only way to know is to read the data sheet or reference manual for your specific device.I have selected examples in SDK. There i t is included the file "xintc. In my case, this file does not exist. Which can be the reason? If you don't include the Interrupt Controller in your design, then the correct files will not be referenced by platgen.

A nother question : I like to to call the function SpiSingleWrite multiple times.

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The problem is, that I see only the first transmission in ISim. The 2nd and 3rd transmission cannot be performed. What could be the reason? Without seeing any ISim screenshots it would be difficult to say. You are neither void ing the functions nor providing a holder for the returned value.

I don't know enough about C to say what would happen in this case. I only see the first transmission. C orrect.

Tutorial 26: Controlling a SPI device using the ZYNQ SPI controller

This is my new SpiSingleWrite-function for debugging. This is determined by the driver. Here's the output :. What is a solution of this problem? The MISO line is always tristate. SPI is effectively a circular buffer. Even though you don't care about the data you specify a NULL for the receive buffer in the transfer functionI would have thought it needed to read some valid data.

Your testbench should really include a model of the other end of the SPI to provide real data. Finally, your MISO line in your testbanch should have a value, probably a pullup on the signal would be enough.

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Secondly, I see no SS being driven. This could be why the Transfer function thinks it is busy. It is still selected from the previous transfer.As I said mechanism is same for each slave.

So copy the code of any slave for the new BUT the array where numbers are stored will be different. Author has used variable i in previous slave code hence I guess he used i1. For every tick 1 bit will be passed. Total address will be of 8 bits.

Shashi, I'm kind of lazy. Is there an easy way to get an Acrobat PDF of your writeup? Please let me know. Hey Jesse, Sorry but I use cloud services for posts and compiling code hence pdf version isn't available from my side. If you are using an Apple product then you can export this page as.

In case you are using Android or Windows based browser, you can use online services to convert webpage to pdf. However in that case, code scripting may get lost.

ZYNQ Training - Session 05 - Designing AXI Sub-systems Using Xilinx Vivado - Part II

Slock is the name of a task. The purpose of slock i. It works in a similar way.

zynq spi example code

I am getting error for the line Slave1 slv1 scl,miso,mosi,ss1 ; The error is : Invalid use of input signal as target. Can somebody please point out whats wrong. If I remove the line Slave1 slv1 scl,miso,mosi,ss1 ; the code is compiled but i am not getting the same rtl schematic as u have got Master and slave both connected.

I am getting the schematic for master only. The line that you're removing has a task that is to instantiate the Slave module and join it with Master with correct ports. Since you are removing the line of code that instantiates and joins Slave to Master, it won't show in RTL view as it is not connected at all.

Order of ports is very important if you are instantiating a module from a module.


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