Programming Flash Devices
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v1.1
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Advantages: Allows local control of programming and data files for maximum security.
The programming algorithms and hardware are available from Actel. The only hardware
required on the board is a programming header.
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Limitations: A negligible board space requirement for the programming header and
JTAG signal routing
Using a microprocessor and an external or internal memory, you can store the program in
memory and use the microprocessor to perform the programming. In Actel documentation,
this is referred to as internal ISP. Both the code for the programming algorithm and the
FPGA programming file must be stored in memory on the board. Programming voltages
must also be generated on the board.
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Advantages: The programming code is stored in the system memory. An external
programmer is not required during programming.
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Limitations: This is the approach that requires the most design work, since some way of
getting and/or storing the data is needed; a system interface to the device must be
designed; and the low-level API to the programming firmware must be written and
linked into the code provided by Actel. While there are benefits to this methodology,
serious thought and planning should go into the decision.
Device Programmers
Device Type Supported: Flash and Antifuse
Device programmers are used to program a device before it is mounted on the system board.
The advantage of using device programmers is that no programming hardware is required on the
system board. Therefore, no additional components or board space are required.
If devices are to be reprogrammed multiple times, or if the quantity of devices to be programmed
is relatively low, a single-site device programmer is the simplest solution. For applications in which
design security is paramount (often the case in military or space designs), the use of on-site
programing maintains design security at all times.
Adapter modules are purchased with the programmers to support the FPGA packages used. The
FPGA is placed in the adapter module and the programming software is run from a PC. Actel
supplies the programming software for all of the Actel programmers. The software allows for the
selection of the correct die/package and programming files. It will then program and verify the
device.
Single-site programmers
A single-site programmer programs one device at a time. Actel offers Silicon Sculptor 3 as a
single-site programmer.
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Advantages: Lower cost than multi-site programmers. No additional overhead for
programming on the system board. Allows local control of programming and data files
for maximum security. Allows on-demand programming on-site.
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Limitations: Only programs one device at a time.
Multi-site programmers
Often referred to as batch or gang programmers, multi-site programmers can program
multiple devices at the same time using the same programming file. This is often used for
large volume programming and by programming houses. The sites often have independent
processors and memory enabling the sites to operate concurrently, meaning each site may
start programming the same file independently. This enables the operator to change one
device while the other sites continue programming, which increases throughput. Multiple
adapter modules for the same package are required when using a multi-site programmer.
Silicon Sculptor I, II, and 3 programmers can be cascaded to program multiple devices in a
chain. Multi-site programmers can also be purchased from BP Microsystems.
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Advantages: Provides the capability of programming multiple devices at the same time.
No additional overhead for programming on the system board. Allows local control of
programming and data files for maximum security.