The instruments designed and developed at SRON commonly incorporate digital logic as part of the electronics hardware. SRON employs a specialized Engineering section for the design, simulation, and verification of these electronics. Its main objective is to design effective and efficient solutions to engineering problems in the realm of digital technology. To this end, the digital electronics section has developed expertise in the following areas:
- Digital Signal Processing (DSP)
- Embedded Processing / System-On-Chip development
- Communication interfaces (SpaceWire, Ethernet, etc.)
The extensive body of knowledge and experience in these three areas provides SRON with the capabilities to design advanced digital integrated circuits that are able to acquire, process, and distribute data using a wide variety of technologies and techniques.
The section's acquaintance with a wide range of technologies provides excellent means to tackle engineering problems in the most efficient and effective way possible. For instance, if a certain task requires a large number of fixed mathematical operations to be performed quickly and repetitively on a set of data, designing a chip based on DSP techniques might be the best option, as it can be optimized to execute one fixed, particular task in the most efficient way possible. However, if the task at hand requires the mathematical operations to be variable (e.g. apply different sets of algorithms under differing circumstances), the use of an embedded processor might be a more favorable choice. This introduces higher flexibility in terms of modes of operation, at the cost of increased power usage and complexity. SRON's comprehensive knowledge in the field of digital electronics has resulted in an extensive track record in successfully carrying out such trade-off decisions.
A modular approach
SRON pursues a well defined design strategy in the development of their digital electronics. The central element in this strategy is to standardize its designs and thereby maximize homogeneity among the various designs developed within the department. This provides many advantages, the most significant being the ability to reuse existing designs in new projects. The majority of our designs are encapsulated in so-called Intellectual Property (IP) cores, which basically represent reusable units of logic. Most of our IP cores are equipped with a standardized peripheral communication interface which connects them to an internal (on-chip) system bus. SRON selected the Advanced Microprocessor Bus Architecture (AMBA) standard developed by ARM as its technology standard for on-chip communication and data transport between IP cores. This design strategy enables us to shorten development time by efficient re-use of previously designed logic, Apart from the AMBA bus, also the SRON proprietary IBUS is used (for Athena/X-IFU and SPICA/SAFARI) and the SKDP bus developed from a third party bus (for SpaceKids and SPEX Airborne).
Cooperation with other Engineering sections
The engineers responsible for the development of digital electronics work in close cooperation with other sections of the Engineering group. The area where this is most vividly demonstrated is in the design of embedded processing systems, or System-On-Chip development. SRON designs System-On-Chip solutions based in Field Programmable Gate Arrays (FPGAs) holding either the LEON3 or ARM9 32-bit microprocessors. This is where the digital electronics and software sections meet in their design efforts. Such joint design efforts enable SRON to take the development of their digital electronics to the next level by combining the strengths of multiple areas of expertise. Although the digital electronics section delivers most of its designs in the form of FPGA's, it also works in close cooperation with the ASIC sub-section for the development of mixed-signal ASICs (i.e. ASICs containing both analog and digital electronics).