QLF08_LaBel.pdf - 第25页
IC and Component Selection for Space Sy stems – Presented by Kenneth A . LaBel 25 Example: Considerations for Selecting a “Custom” Device • Three basic device type options – Custom ASIC (CA) • Also called standard cell o…
IC and Component Selection for Space Systems – Presented by Kenneth A. LaBel
24
Systems Engineering and Risk
• The determination of acceptability for
device usage is a complex trade space
– There is often more than one answer that’s
acceptable
• A more omnidirectional approach is taken
to evaluate the various risks
– Each of the three factors may be assigned
weighted priorities
• The systems engineer is often the “person in the
middle” evaluating the technical/reliability risks and
working with management to determine acceptable
risk levels
IC and Component Selection for Space Systems – Presented by Kenneth A. LaBel
25
Example: Considerations for Selecting a
“Custom” Device
• Three basic device type options
– Custom ASIC (CA)
• Also called standard cell or just ASIC
• Essentially a fully-custom design IC
– Structured ASIC (SA)
• Newer device that is a semi-custom design using built-in
functional blocks that are interconnected for a user’s design
by the device manufacturer
– Field Programmable Gate Array (FPGA)
• One-time or reprogrammable interconnecting of logic
performed by the user or can be done in-circuit
(reprogrammable options)
• These class of devices now have so much
functionality that they can be classified as system
on a chip (SOC)
• We will use the three discussed selection criteria for
this example.
IC and Component Selection for Space Systems – Presented by Kenneth A. LaBel
26
Sample System Implementation for
the Three Styles of FPGAs
Non-volatile memory (NVM) –
holds configuration of FPGA
FPGA
FPGA
FPGA
One-time
Programmable
(OTP)
Non-volatile
Reprogrammable (Flash)
Circuits to interface
between FPGA and
ground for new
configuration uploads
Watchdog/
controller
SRAM-based
Circuits to interface
between FPGA and
ground for new
configuration uploads
Radiation tolerant/hardened options available in all types;
Some are “harder” than others
Increasing
System
Complexity