[HN Gopher] Direct Memory Access computing machine RP2040
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       Direct Memory Access computing machine RP2040
        
       Author : threeme3
       Score  : 140 points
       Date   : 2023-01-21 15:20 UTC (7 hours ago)
        
 (HTM) web link (people.ece.cornell.edu)
 (TXT) w3m dump (people.ece.cornell.edu)
        
       | bullen wrote:
       | Is this the same as the PIO or are those separate?
        
         | argulane wrote:
         | This is seperate from the PIO. It is using the DMA engine to do
         | computation at similar speed to AVR Arduino.
        
         | Dork1234 wrote:
         | You can push the DMA access into the PIO for some real fun.
         | Just wish the PIO had a bit more logic/registers.
         | 
         | https://gregchadwick.co.uk/blog/playing-with-the-pico-pt4/
        
           | monocasa wrote:
           | > Just wish the PIO had a bit more logic/registers.
           | 
           | Seriously. I'd kill for PIOv2 to be some RV32E subset. Hell,
           | I'd take stripped of normal LD/ST instructions if that made
           | it easier for them.
        
       | jevinskie wrote:
       | Also check out the weird machine for an ARM PL080 DMA engine.
       | 
       | https://github.com/jowinter/dmacu
        
       | azinman2 wrote:
       | Is this a class project? I'm very impressed!
        
       | kamranjon wrote:
       | Does this have any practical application or is it more intended
       | to show that it is possible?
        
         | convolvatron wrote:
         | its super cute.
         | 
         | but it turns out to be really useful to allow remote devices to
         | run limited code without interrupting the host. distributed
         | reduction is the easiest application to think of.
        
       | londons_explore wrote:
       | So this seems to only use 3 DMA channels... So by using all 12,
       | you could have 4 additional "cores".
        
       | londons_explore wrote:
       | This is a rather nice route for malicious code to hide itself...
       | A full trace of what the CPU is up to could never find this.
        
       | alexisread wrote:
       | Funnily enough, Amiga and ST blitters did a similar thing a few
       | years back. Notably they were not much faster than the CPU (the
       | 68030 was faster) but the main advantage was the bit shifting as
       | well as the byte transfer functions in parallel with the CPU,
       | that gave them an edge
        
       | drfuchs wrote:
       | Yeah! I/O Channel Processors are back, baby! Now, if only I could
       | find my IBM 370/168 POP manual around somewhere...
        
         | [deleted]
        
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       (page generated 2023-01-21 23:00 UTC)