SRAM on Max II Development Kit

[Altera_Forum]

Hi , 

 I am using the MAX II Development Board and trying to write to the on board SRAM a CypressCY7C1019CV33 , a 128 K SRAM. I have gone through the specs and have written a Module to write and read this SRAM.  My test writes to continuous locations [ 0x0- 0x8 ] and then reads them back.  <<< PLEASE go through the attached code with comments >>>  I was successful in writing a byte and its compliment onto these locations and then read them back.   But when I tried to change  line 115: DataOut = ~DataOut; // Compliment data to   //store in subsequent locations  to   DataOut = DataOut +1 ;  i.e trying to store a counting pattern : I was unsuccessful.  I am observing the SRAMDBus on the oscilloscope and hence can ascertain whether I am able to write and subsequently read that value from the same location.  Though it is obvious that an adder is more logic than an inverter. This logic is completed in the Clock previous to the Cen_bar being asserted. So this should not have made any changes w.r.t to timing and hence I should have been able to write correctly.  I am unable to analyze this weird behavior and will be more than happy to get some light on this.  Thank You

[Altera_Forum]

Hello, 

 I have found the solution to the problem. If anyone faces the same issue. I would suggest try checking the project settings. (right-click on the project -> settings-> device and pin options) and change the default setting for "Device and Pin options -> unused pins" from output driving ground to input tri-stated or input with bus-hold circuitry and everything will work just fine.  :) Thanks to hank from altera support for pointing this out  -neo