Progrmming the EPCS device

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originally posted by kwokwong@Dec 14 2004, 09:00 AM

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i figured out that the epcs.flash contains the fpga configuartion and i can write it to starting at address 0. (am i right?).

i figured out (i maybe wrong) that the epcs_controller_boot_rom.flash - as outout of elf2flash - the application including the boot loader (from flash to ram).

i have compared the content of the epcs.flash with data starting from address 0 and they match to each other.

however i could find the contents of epcs_controller_boot_rom.flash in the flash.

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Hi Kwok Wong,

when you compile and link your software NIOS II IDE creates 'epcs_controller_boot_rom.flash'. This file contains only your software. This is done by blocks starting with 32-Bit Length and 32-bit-Load-Address followed by as many data words as specified in the Length field (in bytes). These blocks are placed in the data fields of the S-records. In my design, I chose the block containing RAM data, load it to the RAM address and jump to the address, the last block (with length field = 0) provided in its address field. (And it works).

When you run Tools->Flash Programmer (in NIOS II IDE) you have to select a configuration, specified in your custom board design together with a reference designator (in the last drop down box). Obviously you have named this configuration 'epcs' because the file 'epcs.flash' is created. This file is much more larger and contains ( I think) all: boot loader, firmware and FPGA configuration. But I couldn't figure out how the original data are merged together.

As cyclone devices accept compressed configuration data, is it possible that all data bytes are automatically compressed then ?

Mike