Something of a shock has hit the world of VMEbus board manufacturers with the End of Life (EOL) notice on the TSI148 bridge chip with some doom-saying the “End of VME.” This news seems to have left suppliers with few options to continue serving customers who are still building and servicing systems with existing board designs. Yet this is a resilient industry and there are already paths forward. Here is one example.
BY TOM WILLIAMS, EDITOR-IN-CHIEF
Like most other VME suppliers, Concurrent Technologies has been using the TSI148 VMEbus bridge device on its current designs. In August 2014, the supplier of the TSI148 device, IDT, notified the industry that it would be going End of Life towards the end of 2015. That was a bit of a bombshell, despite close relationships with IDT, manufacturers had no prior notice and at first it appeared as though they would be left with few options. The reason for the sudden End of Life was that IBM, who makes the device for IDT, are in the process of shutting down the fab and were unable to make a business case to transition the device to an alternate fab. Concurrent Technologies, for one, has reviewed its options and has embarked on a plan to continue VME board supply.
As a result of this end of life announcement, Concurrent Technologies management quickly reviewed the status of its VME product line and also surveyed customers to find out their ongoing requirements. One of the clear messages was that many of the programs that use Concurrent Technologies Intel-based VMEbus processor boards are unable to transition to an alternative architecture due to the complexity of their application, the amount of hardware and software to be ported and the economic and logistic viability of swapping out chassis already deployed in the field. In addition, those customers who are looking to move to an alternative architecture such as VPX need a considerable period of overlap. During this time, which might extend to a few years, they need to continue to purchase existing VMEbus boards to ease their transition.
Essentially, the EOL notice from IDT left manufacturers with a limited number of options: They could issue their own EOLs and walk away from the matter. They could replicate the function of the TSI 148 in an FPGA with the associated expense and delay of redesigning the on-board circuitry. They could aggressively buy up as many remaining bridge chips as possible with no certainty as to how many they might actually need or use. Or they could fall back on the lower-performance but still available Universe-II bridge chip. The path taken will no doubt vary with the circumstances faced by each manufacturer but the following describes Concurrent Technologies approach, which includes the unique step of building a virtually busless VME board.
Fundamentally, it was apparent to Concurrent Technologies that issuing End of Life notices for all its VME products and walking away from this still popular architecture was certainly not an option for them or their customers. Their research delivered some interesting results and established three levels of requirements:
1. Some customers must retain the ability to purchase existing VME boards to satisfy critical program needs.
2. A small but significant group of customers use VME form factor boards in their systems but don’t use the VMEbus for communication.
3. Less than 20% of Concurrent Technologies customers use the higher speed VMEbus transfer protocols like 2eVME and 2eSST. These protocols were extensions to the original VMEbus specification and are supported by the TSI148 bridge.
Customers needed to have firm reassurance regarding the availability of VME products going forward and the solutions already implemented by Concurrent Technologies are:
1. “We issued speedy End of Life notices on all our TSI148 based VMEbus boards to clearly communicate the issue and give our customers time for them to choose a suitable option.”
2. “We are offering extended manufacturing contracts for current generation VME boards. In this case we procure sufficient TSI148 devices to meet the program requirements and store them in our warehouse. These devices are then issued to our in-house manufacturing lines to build boards for the specific customer program on the timescales defined in the contract. Having our own on-site storage and manufacturing facilities means we retain control of the devices and have the flexibility to build relatively small batch sizes. In addition we will be procuring a stock of TSI148 devices to allow us to continue to support repair requirements of boards in the field for several years.”
3. “For those customers not using the VMEbus interface on our processor boards, we have designed a macro-component that fits on our existing boards replacing the TSI148 device. This connects a few key signals from the VMEbus connector and routes them through to our board logic. This enables these boards to respond in the expected way to a number of VMEbus signals like SYSRESET, the VMEbus System Reset. This solution was relatively easy to implement: the printed circuit boards remain unchanged; the TSI148 was replaced and a few associated VMEbus interface components removed; the board logic firmware had a minor update and we released updated board support packages for common OSs such as Windows and Linux. The biggest challenge we faced was updating our internal test suite to use Ethernet as the communication interface instead of VMEbus to allow us to continue to test multiple boards in a single VME chassis. We have very quickly released versions of our popular VP 91x/x1x and VP 717/08x boards with this ‘bus-less’ solution and can repeat this for other products based on customer demand. This option is almost risk free for customers able to avoid VMEbus transfers and removes any current component obsolescence.”
4. “To provide assurance that we will continue to support the VMEbus market, Concurrent Technologies has introduced two new VME boards based on the latest Intel Core i7/i5 and Intel Atom processors (Figures 1 & 2). These boards use the Universe-II VMEbus bridge device which IDT claims will be supported ‘indefinitely’ as it isn’t tied to a specific manufacturing fab. Our expectation is that these two boards will be subject to our standard life cycle: a minimum of 5 years general availability; up to an additional 5 years of extended manufacturing for existing customers; followed by another 5 years of service and repair support. There are some differences between the TSI148 and Universe-II bridges; however we had previously designed boards with the Universe-II and so have all the hardware and firmware expertise to design new boards with this earlier generation device. To ensure the lowest impact at the application level, Concurrent Technologies provides an Enhanced VME Application Programming Interface (API). This API provides a consistent approach to the VME interface on all Concurrent Technologies’ VME/VXS boards and already supported both the TSI148 and Universe-II devices. Previously our VME Application Programming API had helped customers migrate from Universe-II bridge based boards to TSI148 based boards and now it minimizes the changes needed for the reverse migration from TSi148 back to Universe-II. In addition, Concurrent Technologies has produced a Technical Information Note detailing the minor technical differences as a reference for our customers in this transition.”
A sudden EOL on such a vital single source part can be traumatic. Concurrent Technologies reaction shows that there are ways to overcome such events but it takes quick response. These pages will look forward to hearing the reactions of other players. While Concurrent Technologies example may not be the one taken by everyone, it does reflect quick action to acknowledge this specific end of life issue and come up with options to enable customer choice.
The action includes the launch of two brand new VMEbus boards and two new bus-less variants in plenty of time before the end of life deadline to minimize any changes to customer application software through their VME Enhanced API and board support packages. For the small percentage of customers using the higher speed VME transfer protocols such as 2eSST, the company is also offering an extended manufacturing option and has additionally completed an evaluation of an alternate FPGA-based bridge with this functionality. An FPGA-based solution has the advantage of providing independence from specific silicon obsolescence but requires more fundamental hardware and firmware design changes that would have added risk and delayed provision of a choice of solutions in the same timeframe. Doubtless there will be additional discussions and ideas based on customers’ needs to assess what VMEbus solutions they need with the expectation of maintaining a strong portfolio of VME products along with an easy migration path to alternate architectures.