Editing Minimig FPGA

mongo ([http://www.amiga.org/modules/newbb/viewtopic.php?topic_id=39358&forum=8&viewmode=flat&order=ASC&start=140  070728]):<br>
Switching from the Spartan 3 XC3S400 to a Spartan 3E XC3S500E would give you about 17 extra I/O pins while still keeping the 208 pin package. It would also give you a good bit of space for bug fixes and/or future enhancements. The current Minimig design uses up about 82% of the XC3S400, but only 65% of an XC3S500E.<br>
{| class="wikitable"
! Brand !! Chip !! LE/LCs !! IOs !! Package !! Price !! Distributor
|- 
|Altera||CycloneII EP2C8Q208I8||8256||138||208-PQFP||$24.30 || [http://www.digikey.com/ digikey]
|- 
|Altera||CycloneIII EP3C25Q240C8NES||24624||148||240-PQFP || $39.50 || digikey
|- 
|Xilinx||Spartan3 XC3S400-4PQ208C||8064||141||208-PQFP || $19.25 || digikey
|- 
|Xilinx||Spartan3E XC3S500E-4PQG208C||10476||158||208-PQFP || $20.75 || digikey
|-
|Xilinx || [http://www.enterpoint.co.uk/moelbryn/darnaw1.html Enterpoint/Xilinx XC3S1200] || ? || 219 || [[Socket PGA|PGA]] || 110 EUR || [http://www.enterpoint.co.uk/moelbryn/darnaw1.html Enterpoint]
|}
Altera chips are slighlty more expensive than Xilinx's.<br>
It is worth considering the Cyclone III if we want to integrate the 680x0 into the FPGA.<br>
<br>
However if the cpu is integrated into the fpga, the need for a dedicated board is decreased. One can then use a plain developer board which also include onboard sdram and usually some means of fast communication, Like [http://www.digilentinc.com/Products/Catalog.cfm?Nav1=Products&Nav2=Programmable&Cat=Programmable%20Logic Digilent XC3S1600E for 295 USD] or [http://www.enterpoint.co.uk/moelbryn/tarfessock1.html Enterpoint TF1-250E-1600E for 150 GBP].<br>

FrenchShark:<br>
Use as a south bridge, a CPLD like:<br>
{| class="wikitable"
! Brand!! Chip!! Macrocells!! IOs!! Price!! Free Place%Route Linux support
|- 
| Altera|| MAX 3000 EPM3128ATC100-10|| 128 || 80 || $8.60||No
|-
| Xilinx|| XL9500XL XC95144XL-10TQ100C|| 144 || 81 || $5.80 <!-- digikey 070729 122-1372-ND -->||Yes
|}

freqmax: I think that considering Linux support + lower price + consistency with the main fpga. I think that the Xilinx option is better choice.<br>
freqmax: Another consideration is that using an fpga instead of an cpld is that options for larger bus expansions like Zorro bus, Harddisc via ATA etc.. becomes viable. Due capability for faster fpga-fpga communications and more I/Os.<br>
<br>
The slow IOs from Paula and the 8520s can be moved to the CPLD.<br>
On a real ECS/OCS Amiga, IOs from the 8520s are updated at 700 kHz, IOs from Paula/Denise are updated at 3.5 MHz.<br>
On a real AGA Amiga, the 8520s are slightly faster : the IOs are updated at 1.4 MHz.<br>
If we run a high speed bus at 28 MHz between the FPGA and the CPLD, each wire can "transport" 8 IOs from paula or 20 IOs from a 8520.<br>
The CPLD basically acts as a giant IO demultiplexer.<br>
Moreover, the CPLDs are 5V tolerant and non-volatile.<br>
There is an application note from Altera describing how to use a MAX as an IO expander :<br>
[http://www.altera.com/literature/an/an265.pdf AN 265: Using MAX II & MAX 3000A Devices as a Microcontroller I/O Expander]

[[Xilinx XC3S400 and XC3S500E comparison]]<br>
[[Xilinx XC3S500E]]<br>
[[Xilinx XC3S500E pins]]<br>
@@ Line 44: / Line 44: @@
 [[Xilinx XC3S500E]]<br>
 [[Xilinx XC3S500E pins]]<br>
-schmartboard.com adapter:
-:The largest Xilinx Spartan-3 FPGA that has less than 400 pins (20x20 matrix) is the FG320 package: http://direct.xilinx.com/bvdocs/publications/ds099.pdf
-:(FG320 XC3S1500 is also the largest FPGA with Webpack support)
-:The FG320 package is an 18x18 matrix with 1mm pitch: http://www.xilinx.com/bvdocs/packages/fg320.pdf
-:Schmartboard 202-0026-01 is BGA 400 Pins, 1.0 mm Pitch: http://www.schmartboard.com/index.asp?page=products_bga&id=110
-:Diagram of 202-0026-01: http://www.schmartboard.com/schmartboard_pd_202-0026-01.pdf
-:It would be benefitial if someone can clarify this matter.
-Actel FPGA option:
-:[http://www.actel.com/products/pa3/ Actel FPGA] [http://www.amiga.org/modules/newbb/viewtopic.php?topic_id=39358&forum=8&viewmode=flat&order=ASC&start=200 Unit01 070731]
-Xilinx Webpack support maximum: XC3S1500 XC3S1600E