NLP-5x Toolkits
Demo/Emulation Manual
22
P/N 80-0314-A
© 2009 Sensory Inc.
Developing NLP-5x Applications on the NLP-5x Demo/Emulation Board
There are several differences between the way the NLP-5x Demo/Emulation board operates and the actual
NLP-5x chip. The differences arise because the board uses a chip set to emulate the actual NLP-5x. The
chipset consists of a Verisilicon VSI403 Processor, a 64KW SRAM, an FPGA, and a NLP-5x configured for
emulation mode. The NLP-5x chip in the above-named chipset emulates all the functions of the NLP-5x except
for the processor, on-chip memories, and external parallel memory interface.
The NLP-5x’s processor is emulated by the VSI403. It has 32KW of on-chip code RAM that emulates the NLP-
5x’s 1KW Instruction RAM and 31KW (out of 32KW) of the NLP-5x’s Instruction OTP. It also has 16KW of on-
chip data RAM that emulates, and exceeds, the 11KW data RAM of the NLP-5x.
The NLP-5x’s 32KW Expansion OTP memory is emulated by the first half of the 64KW SRAM in the chipset (the
upper half is reserved).
The FPGA in the chipset emulates the NLP-5x’s External Memory Bus.
The major differences between the NLP-5x Demo/Emulation Board and the actual NLP-5x:
Access Speed for Instruction OTP Memory
When the NLP-5x is configured to run at 40 MHz or less, it does not have to be in Turbo Mode, so the NLP-5x’s
Instruction OTP can be accessed at full speed. In this case the VSI403 and NLP-5x throughput are matched.
When the NLP-5x is configured to run faster than 40MHz, it must be in Turbo Mode. In this mode the NLP-5x
processor can run at full speed from Instruction RAM, or when executing tight loops of 8 instructions or less from
the processor’s cache. When running from Instruction OTP, throughput is reduced by as much as one third
because wait states will be inserted when reading the Instruction OTP memory.
The NLP-5x Demo/Emulation board will run
faster
than the real NLP-5x when executing from Instruction OTP.
For most applications that do not approach the performance limits of the NLP-5x, this is not an issue. However,
applications that approach and might exceed the limits of the NLP-5x must be verified on an actual NLP-5x chip.
Access Speed for Expansion OTP, External Memory, and Peripherals
Because these resources are all external to the processor chip in the NLP-5x Demo/Emulation chipset, they are
accessed somewhat slower than with the real NLP-5x. Thus for applications that make heavy use of Expansion
OTP or External Parallel Flash, the NLP-5x-DE emulator will run somewhat
slower
than the real NLP-5x, all
other factors being equal.