Electronics > Beginners
tmm41256p-15 DRAM tester
(1/1)
Homer_79:
Here is the datasheet, for the tmm41256p-15

https://4donline.ihs.com/images/VipMasterIC/IC/TOSC/TOSCS32892/TOSCS32892-1.pdf

I'm doing some work with DRAM, so I thought i'd start with something simple.

This is basically what I want to build, but I thought I would start by understanding how the software works first.
http://www.chronworks.com/DRAM/
http://www.chronworks.com/DRAM/memoryTest.ino

I can follow the code through and it kind of makes sence. Its just an array of 512x512 bits.
But how the decoding of the 9 bits is something im struggling with.

  // First write all Zeros to DRAM
 
  digitalWrite(DIN, LOW);
 
  for(col = 0 ; col < 512 ; col++)
    {
    for(row = 0 ; row < 512 ; row++)
      {
      PORTB = row & 0x3f;            // Write out ROW address ---- Why set all 6 bits to 1's?
      PORTC = ((col & 0x1c0) >> 6) | blue;                              ---- what does this line do?
     
I thought portc would start off at bits 0, not the upper 6

I'm just starting out with arduino, so forgive me learning curve.

many thanks
Navigation
Message Index
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod