Profile • Common instantiations of the CH profile include, but are not limited to: Host Vehicle Interface and Configuration Manager Mission Data Processing Non-Volatile Memory Storage Mass Memory Node The CH node can operate in several capacities, the most essential of which is the Host Vehicle Interface and Configuration Manager. However, several...
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Command and Host Processor Profile
Profile • The Command and Host Processor (CH) profile defines a microprocessor-based solution suitable to construct nodes for mission data processing, spacecraft interfaces, and other applications requiring software execution on microprocessor platforms. The CH profile works alongside the RP Profile and PS Profile to implement nodes within the JAS architecture. The SMAC...
Companion Field Programmable Gate Array
Profile • A separate radiation-hardened companion FPGA is present on the CH node to implement timing functions, custom peripherals, and bridge to proprietary interfaces that may not be directly supported by the microprocessor. The FPGA typically attaches to the microprocessor through industry-standard bus interfaces, though the exact connection method will vary based...
Extended Capabilities
Profile • CH Node Extended Capabilities Customization and extension of CH node capabilities can be realized through instantiations of the Expansion Profile. In instances where custom electronics are needed (for example, spacecraft interfaces or attachments to expansion memory), mezzanines or custom backplane routing to other boards connect electronics to the CH node...
Functional Description
Profile • The CH profile defines the technologies that comprise the CH node, including both required and recommended components to define this standard node type. A CH node should be universally designed to minimize the number of unique instantiations of this profile. A block diagram of a CH node is shown below....
Gigabit Interfaces
Profile • Gigabit interfaces are those that run at line speeds of one gigabit per second and above (>1 Gbps). These interfaces are often tasked with the primary purpose of pushing large amounts of mission data to other nodes for processing. Some examples of these interfaces include: Serial RapidIO SpaceFibre Gigabit Ethernet...
Host Vehicle Interface and Configuration Manager
Profile • The primary role of the CH node in this application is to connect payloads to the host vehicle and to serve as the system controller for payload operations. These functions are implemented through software services running on the radiation-hardened microprocessor. Host Vehicle Interface and Configuration Manager Instantiation A radiation-hardened FPGA...
Mechanical
Profile • The recommended CH implementation is on a 6U VPX board, as defined in the VITA 46 standard and the Mechanical Specification. VPX is preferred for a number of reasons, a few of which include: 3U and 6U board formats to accommodate varying sizes High-density connectors and flexible pinout Availability of...
Megabit Interfaces
Profile • There are several megabit interfaces that may be utilized on the CH node. Some examples of these include: SpaceWire RS-422, RS-232 MIL-STD-1553 CAN bus SpaceWire is the preferred solution for systems requiring data rates below 200 Mbps. SpaceWire links can scale from 2 to 200 Mbps at full duplex and...
Memory Technologies
Profile • There are two types of memory technologies that are highly recommended for inclusion on the CH node: non-volatile flash or EEPROM, and higher-speed SRAM or SDRAM memory. Non-volatile memory is necessary to store the software that the microprocessor will execute upon power-up. Non-volatile memory may also be necessary to store...
Microprocessor
Profile • The CH Node is a microprocessor-based node that executes software stored in supplemental on-board memory. It is highly recommended that this microprocessor be radiation-hardened for reliability. The processor is typically attached to a non-volatile memory technology and a faster SRAM or SDRAM memory. A bus interface between the microprocessor and...
Mission Data Processing
Profile • This application employs the CH node as a mission data processor, utilizing the radiation-hardened microprocessor and on-board memories to perform computations in support of the payload’s mission. Additional optional memories or other board capabilities may be built onto the expansion port if desired. Mission Data Processing Instantiation This application is...
Network Interfaces
Profile • All JAS nodes communicate through a standard set of interfaces that adhere to standard protocols. Refer to the Electrical Specification for physical layer technical information and Communication Specification for details on standard data protocols. This section describes two classes of network interfaces, megabit interfaces with line speeds below one gigabit...
Non-Volatile Memory Storage
Profile • Another common application of this profile is as an interface to non-volatile memories. These memories may contain firmware for FPGA nodes, mission data queued for transmission to the ground, payload configuration parameters, software, and more. Non-Volatile Memory Storage Instantiation In these applications, the CH node software is configured with services...
Power Conversion
Profile • The input power for CH nodes is provided by one or more voltage rails that are distributed throughout the system. This distributed voltage is typically a higher voltage than those required by the components on the board in order to improve efficiency by minimizing losses through distribution. The CH node...
System Monitoring and Communication
Profile • CH Node System Monitoring and Communication An important element that must be included in each CH node is described in the SMAC Profile. The SMAC monitors and controls the state of the CH node. The SMAC also provides standard network interfaces for connectivity to other nodes.
Volatile Memory Storage
Profile • The CH profile may also operate as a low- to medium-performance memory node, hosting volatile SDRAM memories that can store mission data for short periods of time. This application may be used to queue mission data, provide temporary storage of data for processing, and other similar functions. Volatile Memory Storage...