I'm attempting to use the ALS Pmod with the Basys2 board in VHDL.
How would I go about doing so?
With a 3-wire SPI™ communication interface. The Texas Instruments ADC081S021 Single Channel, 50 to 200 ksps, 8-Bit A/D Converter (PDF data sheet) is intended to be polled. Note from the TI datasheet you don't need a full SPI slave interface, it's read only, a simple port. From the schematic for the PMOD-ALS it appears it operates in continuous tracking mode.
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I found on https://github.com/Xilinx/XilinxBoardStore/blob/2020.1.1/boards/Xilinx/au50/production/1.0/part0_pins.xml
two pin names I dont understand. What are purpose of
<pin index="9" name ="FPGA_TXD_MSP" iostandard="LVCMOS18" loc="BB25"/>
<pin index="10" name ="FPGA_RXD_MSP" iostandard="LVCMOS18" loc="BB26"/>
in line 29?
Best'
I have found some information about the pin on the alveo product guide, section Maintenance Connector Interface, which I quote:
The Alveo U50 accelerator card provides access to the FPGA through the
JTAG interface using a debug and maintenance board (DMB) connected to
the 30-pin maintenance connector. The connector pinout supports three
UART debug interfaces: PMBus, FPGA JTAG, and satellite controller
JTAG.
(From here you can dive deeper into the UG1377)
By looking at another u50 alveo PG we can find more info about the satellite controller (page 5).
A TI MSP432 satellite controller resides on the U50/U50 LV card to
control and monitor voltages, currents and temperatures
By looking at the picture, , it seems that the PINs you are searching for are UART pins (TX,RX) to communicate to the TI satellite controller from directly the FPGA.
I have a Xilinx Zybo board. I followed the instructions here and created a custom multiplier over the AXI bus. The multiplier shown on the website processes one input and generates one output. How can I modify it such that it can process streaming inputs sort of like a pipeline. Any hints?
In the tutorial, at Step 5 of "Create the custom IP", select AXI Stream interface rather than AXI Lite. Then modify the HDL source to have the proper signals for a streaming interface (mainly VALID, READY, and DATA). Then follow the rest of the steps to add the IP into your design in Vivado.
Note you'll have to create 2 streaming interfaces, one for input and one for output. Unlike AXI Lite where you can read/write a single register, a Stream is a one-directional flow of data.
EDIT: this doesn't address the way you'd test/stim from the SW side. The example will only work with an AXI Lite interface. You'd need a custom driver to work with the Streaming IF(s)
I've looked over the info on BSCANE2 in http://www.xilinx.com/support/documentation/user_guides/ug470_7Series_Config.pdf (pg 169 7 Series FPGA Configuration Guide) and I can't quite figure out how to use it based on that descriptions.
I want to be able to use the JTAG port on the KC705 board to shift in some configuration data for our design. I think (based on the description there in the user guide linked above) that the BSCANE2 is what I need to do that... but I really don't understand why all of the pins of the BSCANE2 component seem to have the wrong direction (TDO is an input while all of the other JTAG control sigs like TCK, RESET, TDI are outputs). Initially I had thought that there was an implicit connection from the signals of the JTAG port of the FPGA to the instantiated BSCANE2 component, but that doesn't appear to be the case based on the port directions. I suspect I'm missing some information somewhere and while I have read the docs it's still not clear to me how to actually use the BSCANE2 to do what I'm trying to do.
Any example usage of a BSCANE2 component would be appreciated.
NOTE: the description of the BSCANE2 in the user guide linked above says:
The BSCANE2 primitive allows access between the internal FPGA logic and the JTAG Boundary Scan logic controller. This allows for communication between the internal running design and the dedicated JTAG pins of the FPGA
This sounds exactly like what I need.
Xilinx offers a 8 bit CPU called PicoBlaze that uses a JTAGLoader module to reconfigure the PicoBlaze's instruction ROM at runtime. The JTAGLoader is provided in VHDL for Spartans and Series-7 devices.
But I think JTAG is not a good protocol for data transfer. Especially the JTAG software API is a mess.
What about UART? Most boards have a USB-UART bridge like CP2103 that supports up to 1 MBoud.
Hello this will be an experts questions :) You should be familiar with the following topics
Xilinx Multi-Gigabit-Transceivers (MGTs), especially the 7-Series GTX/GTH transceivers (GTXE2_CHANNEL)
Serial-ATA Gen1, Gen2 and Gen3, especially Out-of-Band (OOB) communication
Question:
How should a GTXE2 be configured for Serial-ATA?
OOB signaling is not working neither RX_ElectricalIdle nor ComInit.
Introduction:
I implemented a SATA controller for my final bachelor project, which supports multiple vendor/device platforms (Xilinx Virtex-5, Altera Stratix II, Altera Stratix IV). Now it's time to port this controller to the next device family: Xilinx 7-Series devices, by name a Kintex-7 on a KC705 board.
The SATA controller has a additional abstraction layer in the physical layer, which is based on SAPIS and PIPE 3.0. So to port the SATA controller to a new device family, I have only to write a new transceiver wrapper for a GTXE2 MGT.
As of Xilinx's CoreGenerator doesn't support the SATA protocols in the CoreGen wizard, I started a transceiver project from scratch and applied all necessary settings as far as they are asked by the wizard. After that I copied the GTXE2_COMMON instantiation into my wrapper module, ordered the generics and ports into a meaning full schema.
As a third step I connected all unconnected ports (the wizards doesn't assign all values !!) to their default values (the default from UG476 or zero if not defined).
In step 4 I checked all generics and ports again against the UG476 if they are compatible to the SATA settings. After that I connected my wrapper ports to the MGT and inserted cross-clock modules if necessary.
As of the KC705 board has no 150 MHz reference clock, I program the Si570 to supply this clock as "ProgUser_Clock" after each board "bootup". The MGT is in powerdown mode (P2) while this reconfiguration. When the Si570 is stable, the MGT is powered up, the used Channel PLL (CPLL) locks after ca. 6180 clock cycles. This CPLL_Locked events releases the GTX_TX|RX_Reset wires, which cause a GTX_TX|RX_ResetDone event after additional 270|1760 cycles (all cycles # 150 MHz -> 6,6 ns).
This behavior can be seen in chipscope, captured with a stable, uninterrupted auxiliary clock (200 MHz, slightly oversampled).
So the GXTE2 seams to be powered-up, operational and all clocks are stable.
GTXE2 ports to control the OOB signaling:
The MGT has several ports for OOB signaling. On TX these are:
TX_ElectricalIdle - forces TX into electrical idle condition
TX_ComInit - send a ComInit sequence
TX_ComWake - send a ComWake sequence
TX_ComFinish - sequence was send -> ready for next command
On RX:
RX_ElectricalIdle - RX_n/TX_p are in electrical idle condition (low-level interface)
RX_ComInit_Detected - a complete ComInit sequence was send
RX_ComWake_Detected - a complete ComWake sequence was send
Detailed error desciption:
TX sends no OOB sequences if TX_ComInit is high for one cycle.
RX_ElectricalIdle is always high
Tests:
SATA loopback cable: cut a SATA cable and solder the apropriate wires ;)
-- I'm using a special SFP to SATA adapter, which extends the KC705 with a SATA connector - http://shop.trioflex.ee/product.php?id_product=73
SMA loopback cables: I moved the MGT and connected the LVDS wires to the SMA jacks and installed 2 SMA cables as cross-over.
I programmed my old ML505 (Virtex-5) with onboard SATA connector to send ComInit sequences. The 2 boards are connected with a special SATA cross-over cable.
I connected a HDD with a partial stripped SATA cable to the KC705 (SFP2SATA adapter) and connected a 2.5 GSps scope (yes the signals are undersampled, but it's good to see bursts and idle periods...).
Experiences:
Test 3 shows transmitted OOB sequences from Virtex-5 to Kintex-7 but the ChipScope trigger event does not occur - Rx_ElectricalIdle is still high.
Test 4 shows no transmitted OOB sequences on the cable.
Should I post parts or the complete transceiver instanziation?
only the instance has ca. 650 lines :(
Please ask if you need more information, images, code, ... :)
Appendix:
Electrical idle means that the MGT drives both LVDS wires (TX_n/TX_p) with common mode voltage (V_cm) which is in range 0..2000 mV. If this condition is met, the common mode delta voltage is less than 100 mV, which is referred to as ElectricalIdle condition.
OOB-signaling means that the MGT transmits bursts of electrical idle and normal data symbols (D10.2 in 8b/10b notation) on the LVDS wires. SATA/SAS defines 3 OOB sequences call ComInit, ComWake, ComSAS which have different burst/idle durations. Host controllers and devices use these "Morse signals" to establish a link.
So I think I found some answers to the problem and want to share them.
I started to simulate the GTXE2_CHANNEL hardmacro. The simulation is behaving as "false" as the hardware. So I tried to simulate the MGT in Verilog and used an instance template from here:
http://forums.xilinx.com/t5/7-Series-FPGAs/Using-v7gtx-as-sata-host-PHY-and-there-is-issue-bout-ALIGN/td-p/374203
This template simulates ElectricalIDLE conditions and OOB sequences nearly correct. So I started to diff both solutions:
TXPDELECIDLEMODE, which is a port to choose the behavior of TXElectricalIDLE is not working as expected. So now I'm using the synchronous mode.
PCS_RSVD_ATTR is a unconstrained bit_vector generic of 48 bit. If you have a look into the wrapper code of the secureip GTXE2_CHANNEL component, you will find a conversion from bit_vector => std_logic_vector => string. Internally all generics are treated as DOWNTO ranged. So it's important to pass a DOWNTO constant to the GTXE2 generics!
So now you could ask why is he using to-ranged constants and generics?
Xilinx ISE up to the latest version 14.7 has a major bug in handling vectors of user defined types in unconstrained generics. The default direction of vectors is TO. If you are passing vectors of enums as DOWNTO to unconstrained generics into a component, ISE is reversing the vector elements and "emits" a TO ranged vector in the components !!
This is especially "funny" if the design hierarchy, which uses this generic, is not a balanced tree...
If you are using enums of 2 elements, the problem is not existent -> maybe this enum is mapped to a boolean.
Which task are still open?
TXComFinish is still not acknowledging the send OOB sequences.
I have to investigate this two bug fixes in synthesis and measure the OOB sequences with a scope - this may last some days :)
Edit 1:
Solution for Bug 1:
I have added a timeout counter whose timeout depends on the current generation (clock frequency) and the current COM sequence which is to be send. If the timeout is reached I generate my own TXComFinished signal. Don't or the timeout signal with the original TXComFinished signal from GTX, because sometimes this signal is high while COMWAKE is to be send, but this finished strobe belongs still to the previous COMRESET sequence!
Solution for an other Bug:
RXElectricalIDLE is not glitch free! To solve this problem I added an filter element on this wire, which suppresses spikes on that line.
So currently my controller is running at SATA Gen1 with 1.5 GHz on a KC705 board with a SFP2SATA adapter and I think this question is solved.
I am new to the Zedboard and am working up to transferring a complex hardware accelerator I currently have working on a regular FPGA board. Anyway I want to walk before I can run so have done the Zedboard speedway tutorials and am now toying around with small projects. My first of which being an simple adder accelerator:
-Send 2 numbers to the pl(programmable logic), to reg a and b
-the pl adds the numbers
-an interrupt to the PS(CPU) signals the computation has finished.
-In the ISR the PS reads the result from reg c
For this design I am using 3 registers (a,b,c) in the AXI interconnect, I have created the IP templates using CIP.
Basically though what is the best way send a control signal to enable the addition to the PL. So how should I signal to the PL adder that I have loaded the two numbers in reg a and b and now want to add them?
-Should I create a 1bit signal GPIO interconnect, add a 4th 1 bit control register to the IP? or is there a more 'stylish' way to do this by using the BUS2IPdata signals?
-Or is there another way to create custom PS to PL control enable signals?
Many thanks
Sam
Current idea:
-Build a switch in the user_logic HDL based on the BUS2IPWrCE, so when this is asserted to write to reg B I can then signal an enable signal to my adder? Or will I run into some concurrency issues with the data not being fully written straight away?
So to do this I have created the AXI perph using CIP, then modified the used_logic and two new ports, en and interrupt. Following these instructions I employed these external connections.http://www.programmableplanet.com/author.asp?section_id=2142&doc_id=264841
I then connected these two external connections to GPIO interfaces to provide the required functionality.
In your larger designs, it will be difficult to get performance using a GPIOs to control the scheduling of your accelerators. I suggest setting up FIFOs of command blocks between software and hardware.
For example, your peripheral could implement an AXI Stream slave, to receive commands from software, and an AXI Stream master, to send result indications back to software.
It can assert an interrupt to indicate that there are values in the response FIFO.
For higher performance, set up these FIFOs in DRAM and use AXI read/write masters in your peripheral.