Using Mixed Signal FPGAs for xTCA Hardware Platform Management

By Mark Overgaard, Pigeon Point Systems

The hardware platform management layer of the PICMG, AdvancedTCA, MicroTCA, and AdvancedMC frameworks (collectively, xTCA) has been a key factor in their widespread adoption in communications and other applications. This mandatory layer does “close to hardware” management: tracking the thermal, power, and interconnect aspects of boards, modules, and shelves (or chassis), among other functions. A key aspect is the local management controllers required in each board and module.  

Designers have typically incorporated low-cost microcontrollers such as the Renesas H8S or Atmel AVR. A new alternative uses a mixed signal FPGA, such as Actel’s SmartFusion. The FPGA combines many local management controller functions into a single chip, including monitoring voltages, currents, and temperatures, executing the xTCA-compliant management firmware, and notifying upper management layers of local exception conditions. Furthermore, the single chip can incorporate additional blocks of IP to further optimize it for management applications and even integrate board-specific logic that would otherwise require a separate PLD. The xTCA specifications allow the above functions to be implemented in a standardized way, enabling fully interoperable systems to be built from independently implemented board, module, and shelf components.

IPM Controllers (IPMCs) provide the local board management controller function for AdvancedTCA boards. They are one example of such controllers defined by xTCA. One function of an IPMC is to communicate with the shelf level manager via a dual-redundant in-shelf implementation of the Intelligent Platform Management Bus (IPMB) called IPMB-0. Based on I2C, IPMB runs at 100 Kbps or less in xTCA applications.

IPMCs and other xTCA board and module level controllers can also be connected via an in-shelf Ethernet channel, such as the ATCA Base Interface, which implements 10/100/1000 Base-T Ethernet.  Such “LAN-attached” devices can perform several functions over the connection, including: 1) upgrading the firmware, possibly including programming images for PLDs on the board, 2) accessing serial ports on the board, both for the IPMC itself and for the larger payload processors usually implemented on the boards, and 3) reviewing traces of IPMB interactions involving the IPMC.  These capabilities, when available via LAN, can dramatically benefit the integration and support of a wide range of xTCA configurations.

Mixed signal FPGAs are an excellent platform for implementing advanced xTCA management controllers since they can perform both digital and analog functions. They can thus replace both a microcontroller and other digital and analog logic. They save power and board space, reduce the need for software development, and provide additional flexibility. They make new functions and revisions easier to address. Mixed-signal FPGAs can play a key role in achieving cost-effective, compliant, and interoperable implementations of the mandatory hardware platform management layer in xTCA systems.

For more information, see the Actel/Pigeon Point white paper Using Intelligent Mixed Signal FPGAs for xTCA Hardware Platform Management or visit the Pigeon Point System website.

Mark Overgaard is the founder and president of Pigeon Point Systems, an Actel company. You can reach him at mark@pigeonpoint.com.