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DLPLCR4500EVM: How many images can I upload in the memory of the DLP4500

Part Number: DLPLCR4500EVM
Other Parts Discussed in Thread: DLP4500, DLPC350

I am trying to figure out what is the maximum number of 1bit images that I can upload to the flash memory of the DLP4500 EVM.

I have managed to replace one of the images with a bmp that I created using 24 1-bit images (the size of the bmp ends up being about 3 MB while each 1-bit image is about 1Mbit). However, I don't want to add more that the original 3 flash images because I am afraid I might brick the DLP4500.

I've read in the documentation (DLPC350 DLP® Digital Controller for DLP4500 and DLP4500NIR DMDs datasheet (Rev. F) - -)  that the internal RAM memory is 64 Mbit (Stores up to 48 1bit images), and that it supports 32 MB of external parallel flash for increased pattern storage. 

So to my questions:

Question 1:

The statement about the 32MB is a bit ambiguous to me. Is there 32MB of parallel flash on the DLP4500EVM?

Question 2:

If there are 32MB available would that mean that it is possible to upload about 10 24bit images (since one 24bit image is about 3MB)?

Thank you in advance.

  • Hello User,

    Welcome to the E2E forum and thank you for your interest in DLP technology!

    To address your questions:

    Question 1

    Yes, the DLPDLCR4500EVM contains two parallel SPI flash devices which contain the firmware needed to configure and operate the DLPC350. It necessary these two devices contain the same firmware in order for the DLPC350 to properly function.

    Question 2

    This should be possible so long as the firmware image does not exceed the flash device capacity. The 4500 EVM User's Guide mentions the following in section 3.2.5:

    "Flash images: single-frame, 24-bit Still images stored in external flash memory. The flash memory supports up to 32MB of storage with up to 64 images. The images stored in flash memory support RGB 4:4:4 and YCrCb 4:2:2 pixel data formats."



  • Thanks for the prompt reply. I would appreciate if you could further help me clarify the following. 

    in Question 1:

    you mention that it is necessary that the two devices (I assume the internal RAM 64Mbit and the 32MByte parallel flash) need to have the same firmware for the DLPC350 to function properly. How do I accomplish that? Does it have to do with "skip Bootloader Update"and/or the "Fast Flash Update" on the firmware upload tab (in the lightcrafter UI)?

    Could you provide a reference for me to read in more detail (there is so much documentation that is easy to get lost or miss the relevant information). 

    In Question 2:

    I need some help to confirm the calculation about the maximum number 64 images that is mentioned in the  4500 EVM User's Guide Section 3.2.5. 

    I am mostly familiar with the RGB encoding (I've read a bit about the YCrCb 4:2:2 this morning for the first time). To my understanding the RGB has a lot of redundant information (but its easier to conceptually understand its format), while the  YCrCb 4:2:2 is more efficient it terms of storage (less redundancy).

    To my understanding, the storage size of an (uncompressed) image encoded with YCrCb 4:2:2 requires half the size of an RGB image at the same color depth. 

    So I expect that the maximum number of 64 images refers to images encoded with the  YCrCb 4:2:2  encoding format, while if the image is RGB encoded  then a maximum of 32 (24bit) images is supported. 

    a) is the above statement correct?

    b) How may I encode a bmp image in a YCrCb format and upload it on the firmware ? (is there any tutorial/guide available)?

  • You are welcome to the help.

    Question 1

    The Firmware Upload sub tab under the Image/Firmware tab should go through a process of flashing both devices. Section 3.4 of the DLPDLCR4500EVM User's Guide contains a walkthrough of the upload process.

    Question 2

    a) It is difficult for us to confirm the size that an image might be. Outside of the RGB/YCrCb encoding, resolution and compression techniques will cause the size of an image file to vary. However, once an image is created the properties will be available to you through your windows explorer. This will include the size of the image.

    b) Images can be encoded through image or graphic editing software. GIMP is a free software that might serve your purpose. Methods for changing the color decomposition for images will vary depending on the software, but can be found online.

    Section 3.5 of the DLPDLCR4500EVM User's Guide provides instructions on building images into flash.