Microchip SST26VF064B (64Mbit Serial Flash)


Closed Thread
Results 1 to 6 of 6
  1. #1
    Join Date
    Jun 2005
    Location
    West Australia
    Posts
    116

    Default Microchip SST26VF064B (64Mbit Serial Flash)

    Hi All,

    I have some Microchip SST26VF064B (64Mbit Serial Flash) parts on order and, while I wait for their arrival, I'm wondering if any Forum users have experience using this family or similar with PBPro. A forum search did not yield any results.

    It is a logging application and I want to move away from using SD cards and connectors.

    Anyone?

    Thanks and regards,
    Bill

  2. #2
    Join Date
    May 2013
    Location
    australia
    Posts
    2,379


    Did you find this post helpful? Yes | No

    Default Re: Microchip SST26VF064B (64Mbit Serial Flash)

    my spi flash addin for the tft displays would probably handle those chips , it simply uses however many 64k blocks are needed, each as 16 x 4k pages to cover the expanse
    pretty simple , has r232 serial i/o routines to load in data too.
    personally i would use an esp32/8266 and spiffs or littleFS these days. why struggle with ancient underpowered tech
    Warning I'm not a teacher

  3. #3
    Join Date
    Jun 2005
    Location
    West Australia
    Posts
    116


    Did you find this post helpful? Yes | No

    Default Re: Microchip SST26VF064B (64Mbit Serial Flash)

    Hi Richard,

    Thanks for your input.

    I took a look at your TFT addin and it is heavy going for me to understand what's happening as most is in assembly. I'll try the code when my parts arrive and may have to order some W25Q32BV parts if mine aren't successful.

    I did a search for and read about your suggested file systems, interesting, but I want to keep using PICs. Call me old fashioned however I'm comfortable with PicBasic and find the code environment for Arduino, ESP32, etc,. cryptic and confusing. I'm sure that most of the forum users will agree with me and am surprised routines for Flash haven't attracted much comment or attention.

    Thanks and regards,
    Bill in Perth

  4. #4
    Join Date
    May 2013
    Location
    australia
    Posts
    2,379


    Did you find this post helpful? Yes | No

    Default Re: Microchip SST26VF064B (64Mbit Serial Flash)

    it is heavy going for me to understand what's happening as ̶ ̶m̶o̶s̶t̶ ̶i̶s̶ ̶i̶n̶ ̶a̶s̶s̶e̶m̶b̶l̶y̶ a tiny little bit of assembly code is sprinkled in for speed
    99% of the asm is for usercmd not really code per se.
    i can't see any way to make a flash FS that's any less complex or resource hungry than a fat16 or fat32 sd card system , hardly worth the effort
    for such a tiny storage space. my system was for storing images with a 8.3 file name and their width, height, size in 64k blocks
    the files can span up to two blocks at least [can't remember].
    i spent a week trying to come up with a FS that could allocate the 4k sectors in such a way that files could grow and/or be erased. i was hoping
    to develop a fat that handled a list of free blocks and a linked list of allocated blocks for each file that did not wear out that region of flash.
    the task was simply beyond me. i did come up with this rather manual scheme, it did the job at the time.
    Last edited by richard; - 12th April 2021 at 12:07.
    Warning I'm not a teacher

  5. #5
    Join Date
    Jun 2005
    Location
    West Australia
    Posts
    116


    Did you find this post helpful? Yes | No

    Default Re: Microchip SST26VF064B (64Mbit Serial Flash)

    Hi Richard,

    I take your point however in my logging application I don't need a file system.

    Presently data is being streamed via 4G and the planned logger will be there only to safeguard against Telstra comms failures - not frequent but has occurred leaving 'holes' in data that compromises the modelling. After such an event a second modem port will allow a remote connection to interrogate the logger, search for the time/date wanted and download the missing information.

    I plan on using the Flash as a lump of memory with each 15byte record [GPS time/date stamped+data] being written contiguously. The only housekeeping necessary will be to stay within the bounds of the device's page/block and address limits. I'm using a large Flash size to maximize time before overwriting of cells becomes necessary and expect to get near 1 year of 1 minute records before this happens.

    Any further thoughts or comments you may have are welcome.

    Cheers,
    Bill

  6. #6
    Join Date
    May 2013
    Location
    australia
    Posts
    2,379


    Did you find this post helpful? Yes | No

    Default Re: Microchip SST26VF064B (64Mbit Serial Flash)

    which is what I did. its a way to break up the flash data space
    enabling reading, writing and erasing of data in a pic sized way
    yet deal with large data structures normally beyond a pic's scope.


    search for the time/date wanted and download the missing information.
    just looking at that requirement makes me think a sudo file structure
    would be an enormous advantage ,
    think of flash structure , 125 64k blocks , each block has 16 4k pages .

    each page could hold 256 16 byte records depending on how many records per day/week whatever will fit in a block. eg. a new block[file] every fortnight
    a new page every day sort of thing makes life easy
    {its what i use , a record ever 6 mins) [if your storage is timed accurately the timestamp is redundant]
    you can do a bit of wear levelling by offsetting the day page and have a simple ring structure
    Warning I'm not a teacher

Similar Threads

  1. Spi flash chip example - 8mb flash
    By longpole001 in forum Code Examples
    Replies: 6
    Last Post: - 1st August 2014, 12:00
  2. AT45 Flash problems
    By khufumen in forum mel PIC BASIC Pro
    Replies: 6
    Last Post: - 19th November 2008, 01:42
  3. can't even flash an LED
    By bruno333 in forum mel PIC BASIC Pro
    Replies: 7
    Last Post: - 28th April 2005, 14:27
  4. NEXFLASH serial flash
    By TONIGALEA in forum mel PIC BASIC Pro
    Replies: 0
    Last Post: - 11th July 2004, 21:10
  5. Replies: 0
    Last Post: - 18th November 2003, 09:24

Members who have read this thread : 2

You do not have permission to view the list of names.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts