Honored Contributor
Honored Contributor--- quote start ---
i wish i can use the nios ii ide console to input some command. then the nios can send the control bytes to a ram in fpga. then nios will tell configuring verilog modules for peripheral chips to fetch these control bytes from ram and send out to the chips.[/b]
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there's an in-sytem memory contents editor in the altera quartus ii system; you could use that to edit the memory contents directly.
<!--quotebegin-zhzhn1980@Oct 19 2005, 09:50 AM 1. how to use small c library? --- Quote End --- The small C library has no interrupt support, IIRC. So there's no "scanf". You have to read the characters from the UART yourself, then use sscanf(), atol(), strtol(), strtoul(), or something else to deal with them. --- Quote Start --- originally posted by zhzhn1980+oct 19 2005, 09:50 am--><div class='quotetop'>quote (zhzhn1980 @ oct 19 2005, 09:50 am)</div>
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i don't wanna use any external sram. i've specify the jtag_uart_0 as my stdin and stdout.[/b]
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the stdio library will use quite a bit of on-chip memory.
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originally posted by zhzhn1980@oct 19 2005, 09:50 am
obj/hello_world_small.o(.text+0x34): in function `main':
../hello_world_small.c:78: undefined reference to `scanf'
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scanf() requires interrupt support, thus the full c library.
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originally posted by zhzhn1980@oct 19 2005, 09:50 am
if i choose not to use small c library, the total elf seems to be huge! around 52k ~ 56k. surely i don't want this small module take up all the memory in ep2c35.
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that memory usage looks about right. there's a pile of debug symbol tables in the .elf file; this will not be part of the final program image.
to figure out how much memory you're really using, use the nios2-elf-size command:
nio2-elf-size hello_world_small_0.elf
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originally posted by zhzhn1980@oct 19 2005, 09:50 am
i am still not so familiar with avalon tri-state bridge. do i have to have one in my system if i want my nios to communicate with another ram (not on-chip memory within nios) in the fpga?
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it's the easiest way; the alternative is writing your own glue logic... which will wind up looking like the tri-state bridge.
<!--quotebegin-zhzhn1980@Oct 19 2005, 09:50 AM since this ram is only for control byte storage. it's not necessary to be very large. i still don't know who to implement such kind of structure. i would really appreciate if someone can give me some brief idea. --- Quote End --- That sounds like a job for on-chip RAM.
