What is SUMIT™?


SUMIT™ 1.5 Specification (1.0MB PDF)

SUMIT™ 1.3 Specification (390KB PDF)

SUMIT™ 1.0 Specification (191KB PDF)

ISM™ 1.0 Specification (173KB PDF)

SUMIT-ISM™ 1.0 Specification (435KB PDF)

Backgrounder: What is SUMIT™?

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  1. What is SUMIT™ technology?
  2. What does the word SUMIT™ mean?
  3. What connector is used and why?
  4. What interface signals are included in SUMIT™?
  5. How fast is SUMIT™?
  6. How small is a SUMIT™ connector?
  7. What about the cost?
  8. What are valid SUMIT™ connector configurations?
  9. How can I tell which interfaces are supported on a given board?
  10. Why don't you support a PCI Express™ x16 lane?
  11. Why do you support LPC?
  12. Are pcb CAD libraries available for the connector?
  13. Why does the market need SUMIT™?
  14. What applications need SUMIT™?
  15. Is there a technical standards group supporting SUMIT™?
  16. Is there licensing required for SUMIT™?
  17. Who is supporting SUMIT™?
  18. How do I use SUMIT™ to migrate my PC/104 stack?

What is SUMIT™ technology?   Top
SUMIT is an electromechanical connectorization specification that enables all common serial and legacy chipset expansion busses for next generation products. It is a stackable, I/O-centric, serial expansion approach that is independent of any particular board form factor. It supports PCIe, USB, LPC, SMBus, and ExpressCard signals on a single high-speed connector. A second connector supports additional PCIe lanes.

What does the word SUMIT™ mean?   Top
The word SUMIT™ is an acronym and stands for Stackable Unified Module Interconnect Technology. It is pronounced "Sum it".

What connector is used and why?   Top
A Samtec QFS/QMS double row, high speed, 15.24mm Q-strip connector pair is used. Each connector has 52-pins plus ground on the center blade. The standard part numbers are ASP-129637-01 and ASP-129646-01.

For QMS data, go to http://www.samtec.com/technical_specifications/overview.aspx?series=QMS For QFS data, go to http://www.samtec.com/technical_specifications/overview.aspx?series=QFS

What interface signals are included in SUMIT™?   Top

  • Two x1 lanes of PCI Express™ (including clock and card present)
  • Choice of one x4 lane or four x1 lanes of PCI Express (including clock and card present)
  • Four USB 2.0 channels
  • One ExpressCard channel
  • Two SPI/uWire channels
  • LPC interface with serial IRQ and DMA support
  • System Management Bus (SMBus)/I2C with SMBus Alert
  • Reset and Wake On LAN (WAKE)

How fast is SUMIT™?   Top
SUMIT™ can currently support up to Generation 2 PCI Express data rates of 5 Gbps. This data rate has been tested and verified by the Samtec Signal Integrity group.

How small is a SUMIT™ connector?   Top
The slightly larger QFS connector measures only 22.35 mm x 8.13 mm (0.880 x 0.320-inches) which means that it requires very little real estate on a board or module.

What about the cost?   Top
Cost is a key element in any design. SUMIT™ is defined in such a way so that only a single, one-bank connector can be used. This saves PCB board space plus the cost of an additional connector. By using two smaller, separate connectors instead of one large connector, an expansion or add-in board built with only a single connector can plug directly into other processor or expansion cards populated with both connectors, further reducing overall system cost. It is also possible for just the second connector to be used for applications only needing one PCIe x1 and/or one PCIe x4 lane.

What are valid SUMIT™ connector configurations?   Top
Valid SUMIT™-compatible configurations are as follows: Type A that uses connector A only, Type AB that uses connectors A and B, and Type B that uses connector B only. The selection of which SUMIT™ connectors used is up to the discretion of the designer and their cost/performance goals.

How can I tell which interfaces are supported on a given board?   Top
Yes. The SUMIT™ Working Group defined a "label" for suppliers to use on datasheets or manuals, declaring what interfaces are provides (for SBCs) or are consumed (for I/O cards). Visit the label page here.

Why doesn't SUMIT™ support a PCI Express™ x16 lane?   Top
Since SUMIT is targeting small embedded I/O cards that typically require low power; a PCIe x16 solution is not consistent with its goal. A x16 expansion card by definition is very powerful to require such a large bandwidth for data. Hence, it will require considerable electrical power and the requisite cooling. If an application needs x16 bandwidth, the system designer should look at other architectures such as CompactPCI, COM Express and others that become available in the future. Also x16 would take up the entire connector since it is 34 pair (minimum) to realize a full implementation. SUMIT™ balances maximum amount of I/O bandwidth with a small connector that requires a minimum amount of board space. There are several standard x16 connectors in the industry, so a new one isn't needed.

Why does SUMIT™ support LPC?   Top
SUMIT™ supports LPC because the current chipsets from both VIA and Intel support it. LPC equals easy, low-cost I/O. Sub-USD$5.00 super I/O and serial port chips are available with LPC interfaces. Also, there are FPGA vendors that will license example free source code to show engineers how to generate LPC to ISA bridges utilizing a subtractive decode agent. This allows a designer to quickly develop a solution that requires no BIOS changes.

Are Circuit Board (PCB) CAD libraries available for the connector?   Top
Samtec has joined forces with PCB Libraries, Inc., a CAD library management solutions provider to offer IPC-compliant PCB footprints in different file types. Samtec PCB libraries and footprints save designers hours of tedious, yet critical effort. These libraries allow cut and paste application of package outline, text, and recommended solder pad data. At a minimum, they provide the designer with a significant head start in library generation by providing critical component information in an easily customizable format. Go to http://www.samtec.com/technical_specifications/pad_schematics.aspx?m=pi&nav=1723

Why does the market need SUMIT™?   Top
Technology continues to evolve into faster, smaller, and lower cost solutions. SUMIT™ provides a small, full featured, next generation implementation of the I/O busses needed. With the introduction of the newest generation of Via and Intel Atomô-based ultra mobile embedded processors, SUMIT™ offers a excellent I/O expansion solution for a variety of applications.

What applications need SUMIT™?   Top
SUMIT is designed for applications needing I/O expansion. With both the new generation serial bus structures that are common with laptop and desktops, it serves any number of markets such as industrial control, medical, MIL/COTS, transportation, communications.

Is there a technical standards group supporting SUMIT™?   Top
SUMIT™ is administered by the Small Form Factor Special Interest Group (SFF-SIG).

Is there licensing required for SUMIT™?   Top
No, it is an open standard. However, use of the SUMIT™ and/or SFF-SIG logos are prohibited if a company is not a member of Small Form Factors Special Interest Group.

Who is supporting SUMIT™?   Top
A number of single board computer and I/O vendors have built products, including VIA, WinSystems, VersaLogic, ADLINK, ACCES I/O, and Diamond Systems. Additional manufacturers are announcing products soon.

How do I use SUMIT™ to migrate my PC/104 stack?   Top
By preserving the popular PC/104 ISA Bus connector rather than replacing it, SUMIT™ meets the needs of 70+% of the market that uses 1 or more PC/104 ISA I/O cards. Click here to learn how: to migrate PC/104 CPUs while still using PC/104 I/O cards so that legacy application software doesn't need to be completely re-engineered for PCI, PCIe or USB interfaces.

Last updated August 1, 2011
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