Forum Discussion
Altera_Forum
Honored Contributor
18 years agowill Cyclone III work with unconected VCCA PLL ??
I actually made e board already and didn't connected thous VCCA PLL pins and now my board don't work (I can't program it and software all time is saying "can't access JTAG chain" is that because...
Altera_Forum
Honored Contributor
18 years agoit is my DIY cheap 2 layer board trace width 0.25mm Via hole 0.4mm board cost me 38$ so it is not big money loose, and here is pictures of board with connected VCCA1 pin
https://www.alteraforum.com/forum/attachment.php?attachmentid=319 here is picture of second PCB where I made first drilling test to see if it is possible to drill such hole and gain some drilling experience :) https://www.alteraforum.com/forum/attachment.php?attachmentid=321 https://www.alteraforum.com/forum/attachment.php?attachmentid=320 in 2 layers I managed to route first 2 ball rows + configuration pins for Fast Passive Parallel configuration with MAX3000 and 16Mb parallel flash, the main purpose of this board was to evaluate this new super fast +cheep (totally 5$) configuration scheme :) and in addition I have 50 IOs and I can add external voltage to 4 IO banks, by external power supply(or connect to 3.2V on board regulator), that kind of feature is not supported on any altera Dev.kit, So I have 4 individual IO banks that can by set at any voltage I need :) I choose to use BGA256 package because 144pin package had too small IO count(94), my previous cyclone II had 208 pin package (it was enough), so cyclone III I had only one choice BGA256, where for first 2 rows I can route 124IOs that is by 30IOs more than 144pack :) so 124 is reasonable IO count for connecting some high count devices, ofcourse by data sheet BGA256 pack has 182 IOs, but then I need to make 4 layer PCB which cost about 200$ it is too much for hobby staff, and to get it cheap you must make more than 100 boards and then sell them.