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DLPC900: How many pictures are stored in 512Mbit flash?

Part Number: DLPC900

DLPC900 datasheet says "48 Mbit External Flash Stores up to 400 1-Bit Binary or 50 8-Bit Grayscale Patterns". If we use a 512Mbit flash, how many pictures are stored? I think it can do over 4000 1bit or over 500 8bit in 512Mbit flash. Is my understanding correct?

  • Part Number: DLPC900

    I think DLPC900 can use flash size within 512Mbit. If we use 1Gbit flash with DLPC900, is it impossible because of HW/FW restriction?

  • Hello Uryyy,

    Please see § 7.3.5 Memory Design Considerations (pp 43 - 48) of the DLPC900 data sheet.  This section explains various memory configurations. 

    Please look at § 7.3.5.5.2.2 Combining Three Chip-Selects with one 64-Mbit Flash on page 47. This section explains how to use a single larger flash (64-Mbit or larger).  However note that the DLPC900 controller can only address a total of 48-Mbits of total flash memory, so that anything greater than 48-Mbits will be wasted memory.  

    In some cases larger memories are now less expensive, so that it is still more cost effective to have unused memory space.

    Fizix

  • I will ask a simple question again. How many 8-bit patterns can be stored in MT28EW512ABA1LJS?
  • Hi Uryyy,

    There has been a typo in datasheet. Total flash size is 48MBytes. Total no of 8 bit images that can be stored is dependent on image data i.e compression. If you are getting good compression you can store more images.

    Total Flash size = 50,331,648 bytes

    FW size = 897,408 bytes

    Left space = 49,434,240 bytes

    One 8bit uncompressed image = 1920*1080*8 bits = 2,073,600 bytes

    FW stores images in 24 bit format

    One 24 bit uncompressed image = 3 *2073600 (3 8 bit images)= 6,220,800 bytes

    50 8-bit patterns = 17 24-bit patterns

    Flash required for uncompressed 17 24bit patterns = 6,220,800 * 17 = 105,753,600 bytes = Double of available flash.

    Now depending on compression you can fit more.

    -ykc
  • Thanks -ykc.
    I have 2 questions as shown above explanation.
    1. What do you mean "Double of available flash"? 17 24bits patterns size as 105,753,600 bytes is over left space as 49,434,240 bytes.
    2. 3 8 bit patterns are merge int 1 24 bit patterns when patterns are stored in flash? Is my understanding correct?
    Uryyy
  • Hi Uryyy,

    1. If you use uncompressed images then you will need 105,753,600 bytes which is almost double of available flash space 49,434,240 bytes
    Depending on compression you can fit more images.
    2. Yes

    -ykc
  • Does DLPC900 store compressed images in flash? Is the 48Mbyte flash actually stored 50 8bit(17 24bit) patterns via DLPC900?
  • Yes it store compressed images. It can store 50 8 bit images if compression permits.