Messages in this thread | | | From | Paul Miller <> | Subject | pc104 ISA bus-mastering & custom hardware | Date | Sat, 26 Feb 2005 08:20:30 -0600 |
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I've been thinking about fabricating my own hardware for a pc104 board that uses a 16-bit ISA bus. Basically, I want to interface a DSP such that it has access to the pc104's shared memory. I'm fairly confident that I can work out the circuit design, but I need to know more about Linux's ISA support.
1) What is needed to support ISA bus-mastering? I would like the ISA device to write directly to the pc104's shared memory.
2) What memory regions can I write to? Am I limited to <16MB or is it more restrictive? 64K-1MB, 15-16MB?
3) How can I reserve a specific memory region? How much memory can I use? I plan to have a way to communicate to the DSP (via I/O) what memory address to access.
4) How do I enable a 16-bit DMA channel? Do I need to do anything beyond enabling DMA?
5) What are some good examples?
6) What else should I be thinking about?
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