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Ayodele Stephenson
USA
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Posts 57
04 Jan 2010 16:50
| It's Great to see such positive progress, I guess in some ways we will have an even more "modern" Natami, simply because of the need to work with Ram controller, hopefully this will allow for additional performance gains with the "custom chips" Good Work!!
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Erik Bauer
Italy
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Posts 227
04 Jan 2010 17:29
| Thomas Hirsch wrote:
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Light at the end of the tunnel.
Yes, there is. But unfortunately because the memory went from asynchronous to to fully registered and pipelined almost all components need to be "reconsidered" to a certain point. But to show a little bit of progress:
There are still some problems regarding the memory controller - but in general the memory management begun to work. So this is a screenshot of the working copper. The copper can now read chipram memory and write DFF register addresses. At the same time this copperlist is processed by the copper the processor (M68k) is running and can read the copperlist out of the memory:
This second picture is a screenshot of TeraTerm (serial port terminal program) which is connected to the debug serial port of the SyncZorro CPU card.
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GREAT!
My favourite Amiga piece of Hardware showing it's heartbeat in the Natami debug board!! I'm so excited about it! I can't understand what you mean with "because the memory went from asynchronous to to fully registered and pipelined almost all components need to be "reconsidered" to a certain point"
But I guess you know what you're doing. Keep it up!
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Channel Z
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Posts 213
04 Jan 2010 19:12
| @Erik Bauer My guess is that in the first design chip RAM was to be asynchronous SRAM. In the current design chip RAM is buffered synchronous DRAM (DDR2), and thus some design concepts have to be reworked. And maybe Thomas didn't realize that until trying them out on the physical board.
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Marcel Verdaasdonk
Netherlands
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Posts 2089
05 Jan 2010 07:54
| Probably the timings need tweaking since now it isn't a clock a read, we need to do 4 sequential reads, that is where Angus and some of the chips will need to be modded for.
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Claudio Wieland
Germany
| | (Natami Team Member)
Posts 364
05 Jan 2010 08:25
| IIRC, the Natami DDR2-RAM is programmed for a 4-burst access. Since DDR2 delivers 4 databits per pin and external IO clock, we should get (4 cycles)*(4 dbits/pin)*(16 data pins) = 256 bits of data with each burst access with length = 4 per module. Since there are two DDR2 modules (CHIP and FAST) with independent buses, maximum should be 512 bits per burst access. If this isn't completely correct, please clarify. The old memory access access scheme was quite "simple". However, to get DDR2 to its maximum throughput possible, the memory accesses have to be optimally scheduled. That is what this is all about, I guess.
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Gunnar von Boehn
Germany
| | (Natami Team Member)
Posts 3727
05 Jan 2010 09:19
| Claudio Wieland wrote:
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IIRC, the Natami DDR2-RAM is programmed for a 4-burst access. Since DDR2 delivers 4 databits per pin and external IO clock, we should get (4 cycles)*(4 dbits/pin)*(16 data pins) = 256 bits of data with each burst access with length = 4 per module. Since there are two DDR2 modules (CHIP and FAST) with independent buses, maximum should be 512 bits per burst access. If this isn't completely correct, please clarify.
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Natami DDR2-RAM is programmed for a 4-burst access : correct
DDR2 delivers 4 databits per pin: DDR2 does 2 per pin.
The 4-burst access accounts for the 2 transfer of DDR2 already.
This mean:
a 16bit memory interface does 64bit bursts.
a 32bit memory interface does 128bit bursts. I hope this helps. But in general you were right.
The original AMIGA did do single memory access and did wait for it to fully complete until doing the next single memory access.
The Natami originally behaved 100% the same. The new Natami changes the memory access in two ways.
a) It always burst.
Every read access is done in burst lines.
Writes access also burst but the Natami can mask individual bytes - therefore its possible to write single bytes or words as usual. b) The Natami holds several access in flight.
To improve memory performance the NATAMI does not do a single memory access as the old AMIGA but can hold up to 8 burst access in flight per chip/fast bank. The concept of keeping multiple burst in flight is crucial for state of the art memory performance.
This required some significant enhancements to AGNUS. Cheers
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Louis Dias
USA
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Posts 33
05 Jan 2010 18:34
| I see the change in memory controller explains the long silence... Details, details! Nice simple copper list effect. What resolution and frequency is that display?
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Bartek K
United Kingdom
| | (Natami Team Member)
Posts 1330
05 Jan 2010 18:57
| Louis Dias wrote:
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What resolution and frequency is that display?
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I second that question. ?
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Thomas Hirsch
Germany
| | (Natami Team Member)
Posts 233
06 Jan 2010 20:33
| 800x600 50Hz, meaning a total of 628 lines and 902 pixels
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Louis Dias
USA
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Posts 33
06 Jan 2010 20:58
| Aw shucks! :) Show us something a "normal" Amiga couldn't do. ;-)
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Hagbard Celine
Norway
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Posts 13
08 Jan 2010 13:01
| Thomas Hirsch wrote:
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Light at the end of the tunnel.
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I can see the light!!
Wonderful work!
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Channel Z
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Posts 213
08 Jan 2010 13:51
| @Louis Dias
800x600 planar non-laced? :)
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Thundery End
United Kingdom
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Posts 31
09 Jan 2010 01:04
| Gratz on getting a display out considering you went from an SRAM system to a DDR2 RAM based system, it's not like people routinely design and implement memory controllers for a computer that was so tightly tied to its RAM and DMA engine.
*BOWS*(Is not worthy :) )
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Thomas Hirsch
Germany
| | (Natami Team Member)
Posts 233
14 Jan 2010 12:20
| bitplanes The bitplane DMA has ram access now. Each plane now uses a buffer of 32 byte to store incoming data. The data receiving path is now detached from the read access initiating logic. 
The red lines in the picture show the display window limits. Plane one (yellow) and two (red) are drawing a lores circle. The planar data is read from chip memory. For now a line is drawn only once not twice leading to a 2:1 display field.
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Guillaume Michalakakos
France
| | (Natami Team Member)
Posts 144
14 Jan 2010 12:47
| Congratulations Thomas ! It's great to see some good progress. Cheers.
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Bartek K
United Kingdom
| | (Natami Team Member)
Posts 1330
14 Jan 2010 13:50
| Hallo Thomas, Thank you for the update! Good luck!
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Marcel Verdaasdonk
Netherlands
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Posts 2089
14 Jan 2010 14:27
| Yep, mind blowing. I am sure some heads will explode. :P
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Erik Bauer
Italy
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Posts 227
14 Jan 2010 16:50
| Cool! Keep us updated! We do love seeing progress step by step!
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Ayodele Stephenson
USA
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Posts 57
14 Jan 2010 17:44
| This brings a :-D to my face!!
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Hagbard Celine
Norway
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Posts 13
14 Jan 2010 22:02
| Ayodele Stephenson wrote:
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This brings a :-D to my face!!
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Second that :D
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The team will post updates and news here