FlyingDutch
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Hello,
it comes into my mind such idea: extend AVR Soft-Core described in this post:
https://www.edaboard.com/showthread.php?388251-AVR-Soft-Core-(ATMega103)-issues-during-synthesis-and-implementation
by new instruction. I mean adding to the original design VGA framebuffer and extending "Instruction Set" (ISA) of this soft-CPU by one instruction "vgaprint". I would like to extend "instruction decoder" and "executive system" of AVR soft-core by such instruction. The VGA framebuffer will have 24 rows and 40 columns, so the fo9rmat of new instruction would be:
vgaprint(row, column, ASCI_character)
It would be an assembler instruction recognizable by AVR CPU - CPU would be able to perform such instruction and print asci_character on VGA screen.
There are two questions related to such idea:
1) Extending AVR soft-core by VGA screenbuffer (being able to print ASCII character) and extending this CPU instruction set by such vgaprint instruction. I think that after spending respectively long time for such task I should be able to do such alteration.
2) Extending AVR compiler (for example AVR-GCC) by one assembler instruction "vgaprint", and this seems to me be much difficult.The C compiler (and linker) should know how to translate such instruction to binary code (in the form undersdtandable by soft-core AVR CPU).
Could someone give me hints for described task 1) and 2) ? I also be grateful for pointing literature related to such tasks.
Thanks in advance and regards
it comes into my mind such idea: extend AVR Soft-Core described in this post:
https://www.edaboard.com/showthread.php?388251-AVR-Soft-Core-(ATMega103)-issues-during-synthesis-and-implementation
by new instruction. I mean adding to the original design VGA framebuffer and extending "Instruction Set" (ISA) of this soft-CPU by one instruction "vgaprint". I would like to extend "instruction decoder" and "executive system" of AVR soft-core by such instruction. The VGA framebuffer will have 24 rows and 40 columns, so the fo9rmat of new instruction would be:
vgaprint(row, column, ASCI_character)
It would be an assembler instruction recognizable by AVR CPU - CPU would be able to perform such instruction and print asci_character on VGA screen.
There are two questions related to such idea:
1) Extending AVR soft-core by VGA screenbuffer (being able to print ASCII character) and extending this CPU instruction set by such vgaprint instruction. I think that after spending respectively long time for such task I should be able to do such alteration.
2) Extending AVR compiler (for example AVR-GCC) by one assembler instruction "vgaprint", and this seems to me be much difficult.The C compiler (and linker) should know how to translate such instruction to binary code (in the form undersdtandable by soft-core AVR CPU).
Could someone give me hints for described task 1) and 2) ? I also be grateful for pointing literature related to such tasks.
Thanks in advance and regards