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Comparison of Zynq SoMs

May 18, 20156 minutes

Comparison of Zynq SoMs

In the last year or so, there has been an explosion in the availability of System-on-Modules (SoMs) featuring the popular FPGA+ARM combo Zynq-7000 SoC from Xilinx. I’ve always promoted the idea that FPGAs and SoCs allow for faster design cycles and rapid proof-of-concept, but these SoMs take that advantage to another level. Let me explain why. In the past, I would handle most projects by doing a proof-of-concept on an evaluation board, then designing a custom board that integrates all the required components onto a single PCB. While this process is fairly straightforward and minimizes my risk in designing the final custom board, it still has its drawbacks:

  • Lack of appropriate FMCs. Sometimes the customer’s I/O needs can’t be satisfied by an off-the-shelf FMC, so a custom FMC must be developed. This means more time and money spent on a board that will not be used in the final product most of the time.
  • Eval boards are not customizable. Evaluation boards typically contain every peripheral imaginable, the problem being that they all connect to the FPGA and use up valuable I/Os that could have been used for something we actually needed. In most cases the customer only needs Ethernet, USB and an SD memory card.
  • Eval boards aren’t made to leave your desk. Apart from PCIe applications, eval boards typically don’t have a form factor that is small enough or rugged enough for testing in the field or in a product enclosure. Think of putting one in a drone, in a vehicle or in a camera housing - not happening.

My last point is the most important one because most companies these days want a proof-of-concept or a prototype that can be tested in the field or in their product enclosure. This usually isn’t possible with eval boards, but it often is with SoMs. The major advantage that SoMs have over eval boards is that they can be used to develop prototypes that are appropriate for the environment/enclosure in which they will be used. On top of that, some SoMs are manufactured in large quantities, have a good supply from reliable companies and can be seriously considered for use in the final product.

Here are some of the benefits of the SoMs when compared to evaluation and development boards:

  • They’re typically 10x cheaper ($50-$500 compared to $500-$5000)
  • They’re physically smaller, more rugged and more easily integrated into a product enclosure
  • They usually have better availability
  • They’re more easily adaptable to specialized needs

So let me describe a typical design experience with a SoM. My client wants an image processor with 16 image sensors connected to the Zynq-7000. I propose a Zynq SoM so that I can leverage all the work that has gone into the board design, plus kickstart the FPGA design with the provided code examples. I design a custom carrier for the SoM with 16 image sensors - the PCB is only 4-layers and is trivial because I don’t have to route an FPGA or DDR3 memory. In a short time, we have a working prototype that fits nicely into the product enclosure and the client can start putting it in front of customers. Going from here to the final product can take many paths, but the important thing is that my client now has something that is presentable to the market, and he got there with a minimum of delay and expense.

Here is my take on a few of the Zynq-7000 SoMs on the market at present.

 

MicroZed

Arguably the most popular Zynq SoM due to its affordability and being one of the first on the market in this space, the MicroZed from Avnet is a versatile SoM, great for integration into custom designs, but also can be useful as a stand-alone development board.

 

  • XC7Z010-1CLG400C
  • 1 GB of DDR3 SDRAM
  • 128 Mb of QSPI Flash
  • 10/100/1000 Ethernet
  • USB 2.0
  • USB-UART
  • 100 User I/O (50 per connector)
  • 2x6 Digilent Pmod® compatible interface providing 8 PS MIO connections for user I/O
  • User LED and push switch

microzed

 

 

PicoZed

Designed for better integration into custom designs, the PicoZed from Avnet is similar to their MicroZed product but they’ve basically pushed all the interfaces through the expansion connectors so that you only use what you need. This reduces the cost of the SoM and relaxes the mechanical constraints on your design because you choose where to put the bulky connectors. There is also a version of the PicoZed with gigabit transceivers.

 

  • XC7Z010 or XC7Z020 or XC7Z015 or XC7Z030
  • 1 GB of DDR3 SDRAM
  • 128 Mb of QSPI Flash
  • 4 GB eMMC
  • 10/100/1000 Ethernet PHY
  • USB 2.0 PHY
  • XC7Z010
    • 113 User I/O (100 PL, 13 PS MIO)
  • XC7Z020
    • 148 User I/O (135 PL, 13 PS MIO)
  • XC7Z015
    • 138 User I/O (125 PL, 13 PS MIO)
  • XC7Z030
    • 148 User I/O (135 PL, 13 PS MIO)
    • 4 GTX Transceivers

picozed

 

Z-Turn

Although similar in appearance to the MicroZed, the Z-Turn from MYIR differentiates itself with a few different features. A HDMI interface makes it interesting as a single board computer, while the onboard accelerometer could be useful for mobile applications or IoT devices.

 

  • Xilinx XC7Z010-1CLG400C (Zynq-7010) or XC7Z020-1CLG400C (Zynq-7020)
  • 1GB DDR3 SDRAM (2 x 512MB, 32-bit)
  • 16MB QSPI Flash
  • 1 x 10/100/1000M Ethernet
  • 1 x CAN
  • 1 x Mini USB2.0 OTG
  • 1 x USB-UART debug interface
  • 1 x HDMI (supports 1080p resolution)
  • 90/106 user I/O (7010/7020)
  • USB power supply or DC 5V/2A
  • Onboard three-axis acceleration sensor and temperature sensor
  • 5 x LEDs (3 x User LEDs, 1 x Power indicator, 1 RGB LED)
  • 1 x Buzzer

myir-z-turn

 

TE0720

Maybe the smallest Zynq SoM on the market, the TE0720 from Trenz Electronic delivers a lot of features for your real-estate and would be great for especially rugged applications.

 

  • Xilinx Zynq Z020 SoC
  • ARM® dual-core Cortex™-A9
  • 10/100/1000 tri-speed Gigabit Ethernet transceiver (PHY), SGMII accessible on a board-to-board connector
  • USB 2.0 high speed ULPI transceiver
  • 32-bit-wide 1 Gbyte DDR3 SDRAM
  • 32 Mbyte SPI Flash memory (for configuration and operation)
  • 4 Gbyte e-NAND (up to 32 GByte)
  • 2 × 100-pin and 1 x 60-pin high-speed expansion connectors
  • 152 FPGA I/Os (75 LVDS pairs possible) and 14 MIOs available on board-to-board connectors

 

TE0720

 

Mars ZX3

A really innovative concept from Enclustra, designed into a SODIMM form factor, the Mars ZX3 offers 108 I/Os in a small but mainstream package.

 

  • Xilinx Zynq-7020 AP SoC in the CLG484 package (XC7Z020)

  • ARM® dual-core Cortex™-A9

  • Xilinx Artix™-7 28 nm FPGA fabric

  • SO-DIMM form factor (67.6 x 30 mm, 200 pins)

  • 108 user I/Os

    • ARM peripherals (SPI, SDIO, CAN, I2C, UART)
    • FPGA I/Os (single-ended, differential or analog)

  • Gigabit Ethernet and USB 2.0 OTG PHYs

  • Up to 1 GB DDR3 SDRAM

  • 512 MB NAND flash

  • 16 MB quad SPI flash

  • Single 3.3 V supply voltage

mars_zx3_1000

 

Zynq MMP

The only Zynq SoM on the market that carries the largest in the Zynq-7000 family, the Zynq MMP from Avnet is loaded with either the XC7Z045-1FFG900 or the XC7Z100-2FFG900. The Zynq MMP targets applications that require a great amount of FPGA resources or up to 8 gigabit transceivers.

 

  • Dual ARM® Cortex™-A9 MPCore™
  • Up to 800 MHz operation
  • 1 GB DDR3 memory
  • 256 Mb Quad SPI Flash
  • 128MB parallel Flash (PL side)
  • Micro SD card cage
  • 4 GB micro SD Card Included
  • 10/100/1000 Ethernet
  • USB USB 2.0 port
  • USB UART
  • 8KB I2C EEPROM
  • 132 User I/O via module connectors
  • 8 GTX transceivers via module connectors

zynq-mmp