Gameduino/FPGA

clock

using xilinx DCM (we have to generate 50 Mhz clock cfr gameduino, from a 16Mhz external osc)

• Xilinx app note 462 documents DCM for spartan 3

http://www.xilinx.com/support/documentation/application_notes.htm

• xc3s400a (our dev board) has 4 dcms - so that's plenty (gameduino uses one to convert 50Mhz clock to 25Mhz VGA pixelclock)
• dcm-wizard generates a template for component inclusion with right paramaters
• success

synthesize verilog code

• http://excamera.com/sphinx/gameduino/making.html
• http://excamera.com/files/gameduino/ (contains tools and xilinx project files etc)
• http://excamera.com/files/xilinx-sample/ minimal makefile

i get gameduino compiled for the specific fpga it's written for (xc3s200a-4vq100) our dev-board (xc3s400a-5ft256) is not happy with it...

ICAP_SPARTAN3A

Checking expanded design ...
ERROR:NgdBuild:604 - logical block 'ICAP_SPARTAN3A_inst' with type
   'ICAP_SPARTAN3A' could not be resolved. A pin name misspelling can cause
   this, a missing edif or ngc file, or the misspelling of a type name. Symbol
   'ICAP_SPARTAN3A' is not supported in target 'spartan3'.

reason: typo in makefile !!! duh

bmm

there's no problem with this, but investigate the block memory config (.bmm) -- study material : xilinx spartan3a user guide (ug331.pdf), chapter 4, 'using block ram'