FPGA Safety
Implementation
By Allen Hsu and Steve Yang, Doosan
HF Controls Corp.
Allen Hsu
Allen Hsu designed and tested
industrial distributed control system for
power plants, water treatment facilities,
petrochemical
process plants,
and cement plants.
Hsu designed
and programmed
software on
controllers,
peripheral devices,
and host computers.
He designed and
programmed
software for
digital and analog
control interpreters
and networking
software. Hsu
is familiar with
HFC control system architecture and
network communication scheme, Intel
microprocessors used in HFC, the
Assembler language programming, and
the Microsoft Visual studio environment.
He had experience to supervise system
hardware and software development
teams for advanced distributed control
systems, burner management control
systems, and nuclear plant control
systems. Hsu had experience to handle
the multiple overall projects execution
of Nuclear Power Plant Control System
in HFC.
He has been the President & CEO of
Doosan HF Controls Corp. since 2007.
Hsu has a MS in Computer Science
from the University of Texas at Dallas.
Executive Summary
Field Programmable Gate Arrays
(FPGAs), as programmable logic
devices (PLDs) have gained interests for
implementing safety I&C applications
in nuclear power plants (NPPs) owing to
the FPGAs’ specific advantages over the
currently more common microprocessor-
based digital I&C applications.
There are commonalities between
FPGA-based and microprocessor-based
I&C application de-
velopments.
The
FPGAs are viewed
as a mix of hardware
and software. The
development lifecy-
cle of software and
hardware therefore
can be applied to the
FPGA-based I&C
applications as in the
case for micropro-
cessors-based
ap-
plications. To reach
high confidence and
reliability in the
implementations of
the FPGAs applications, it is necessary to
follow the lifecycle development process
that is consistent with the IEEE Std 1074,
IEEE Standard for Developing Software
Life Cycle Processes
, and the rigorous
V&V methodologies that are defined in
IEEE Std 1012,
IEEE Standard for Soft-
ware Verification and Validation
, as much
in the implementations of microproces-
sors-based applications.
However, the specific implementation
of the FPGA-based I&C applications is
very unique and has its own characteristics
that are also dictated by the FPGA manu-
facturers. The implementation activities of
the FPGA architecture and design involve
the FPGA programming, coding, simula-
tion and binary file generation processes.
The paper presents a detailed
implementation process of FPGA for
safety I&C applications in the light
of a successful case for one of the
NPPs, I&C upgrade using FPGA-based
components to replace the obsolete Intel
8085 Microprocessor-based controllers,
where FPGAs emulates the process of the
existing microprocessors and interprets
the execution of the CPU processing.
To validate the implementation and
ensure that the end user’s functional
requirements are fully met, it is critical
that functional and structural as well as
simulation tests be performed with well-
constructed test design/cases and the
FPGA manufacturer’s tools be evaluated
and qualified for their suitability in use.
The FPGA simulation test is an essential
part of the FPGA implementation. The
simulation related tools qualification is
integral of the FPGA simulation tests.
Background
FPGA, as a mature technology used
in commercial, industrial and military,
has been aggressively adopted by the
nuclear power industry. One factor is
that FPGAs can bring cost reduction in an
I&C digital upgrade because FPGAs can
provide simpler licensing process than
microprocessor-based digital I&C, and
FPGAs can be implemented efficiently
within a normal outage period. Simpler
and more effective safety justification and
dependability assessment can be a very
significant contributor to cost reduction.
The cost benefits plus improved test-
ability of the overall architecture provide
reasonable justification for the imple-
mentation of FPGA-based applications in
NPPs. These applications will cover the
full range from highly safety significant
reactor protection systems to non-safety
interface modules. While there are many
papers that cover FPGA subjects in the
nuclear power industry, however, very
few papers describe the implementation
of successfully deployed applications.
This paper will present one
successful case for
Yong-gwang Nuclear
Units
3
and
4
. (YGN Unit 3&4) I&C
upgrade using FPGA-based components
to replace the obsolete Intel 8085
Microprocessor-based controllers.
Implementation
The purpose of the upgrade is to
resolve the component obsolescence
issue. The redesign uses a FPGA to
replace the 8085 microprocessor, the
8155 peripheral device, the static RAM,
and various digital logic ICs used on the
original design. The redesign is required to
be form, fit, and functionally compatible
with the original AFS-SBC01 (single loop
32
NuclearPlantJournal.com Nuclear Plant Journal, January-February 2016
FPGA Implementation for Safety I&C
Applications
