ECC memory

Comments

• Rayman Posts: 13,894

  2020-03-07 03:21

  I was just reading this wiki page; https://en.wikipedia.org/wiki/Soft_error#Soft_error_mitigation
  
  I think it may the combination of low memory count and high memory size (physical volume) that makes it so you don't see soft errors in microcontrollers...
• Rayman Posts: 13,894

  2020-03-07 03:25

  Actually, I was just reading that redundancy is a good what o mitigate any of this:
  https://www.st.com/content/ccc/resource/technical/document/application_note/15/54/c4/5d/90/ed/4f/ce/DM00220769.pdf/files/DM00220769.pdf/jcr:content/translations/en.DM00220769.pdf
  
  If it really matters, I guess make a twin copy of every variable and make sure they are identical before doing anything...
  
  Still, I think ECC would ease minds...
• cgracey Posts: 14,133

  2020-03-07 03:29

  6T SRAM cells have positive feedback for holding state. Much smaller DRAM is 1T, only, needs to be refreshed, and is more easily upset.
• evanh Posts: 15,188

  2020-03-07 04:03 edited 2020-03-07 04:04

  I've had an external battery backed 32 kB SRAM flip a single bit on me after several years. It was in a servo controller that stored the source code on board and tokenised it on every power up. So the controller started spitting out a single syntax error to the comport on every power up. Edited the source, one character had changed, and away it went again.
  
• Rayman Posts: 13,894

  2020-03-07 04:10 edited 2020-03-07 04:12

  cgracey wrote: »

  6T SRAM cells have positive feedback for holding state. Much smaller DRAM is 1T, only, needs to be refreshed, and is more easily upset.

  
  Ok, that seems right. Thanks.
  
  BTW: What does 6T mean? Is this the area of the cell?
• rogloh Posts: 5,168

  2020-03-07 04:21

  6 transistor
• Electrodude Posts: 1,621

  2020-03-07 04:21 edited 2020-03-07 04:22

  Rayman wrote: »

  What does 6T mean?

  
  Number of transistors. Two weak inverters (two transistors each) in a loop, plus two more transistors to access the state (read or forced override) makes six transistors.
  
  Schematic here