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TMS320F28334: using TMS20F28335ZAYA instead of TMS20F28334ZAYA

Part Number: TMS320F28334

Dear Sir  ,

we have old product that use  the c2000 TMS20F28334ZAYA  , due to component shortage  can we use TMS20F28335ZAYA   instead

without changing  the software  (it have the same pinout  / functionality ) , the only difference i see the 28335 have more flash.

you advise please ?

  • You are correct that the only difference is the flash, however, there are a few differences other than the pure size(28335 has 2x flash as 28334). 

    To keep the number of sectors the same(8), the sector size on the 28334 is 16K x 16 , where as the 28335 is 32k x 16.  This changes the size of the sector which impact the min size of flash you can erase as well as the span of that erase. 

    I've added a table below to show how this maps out between the 2 devices.

    For example, if you were erasing Sector C on F28334 after the initial program of the device, the erase function on the F28335 if passed to it Sector C would invoke erase on the addresses that were associated with SectorE and SectorF on F28334, since the argument passed to the Erase API is the sector #(from 0 to 7).

    So, not only are the incorrect address erased(since your cmd file would still be placing contents in Sector C as defined for F28334), but if you corrected and now erased Sector B on F28335, it would also erase the addresses there were associated with Sector D on the F28334.

    From a code operational POV, I can't see this has any effect, and since the initial program of the flash would erase all sectors it wouldn't matter.  If you don't have the above conditions of updating flash, then I don't think you will need to make any code changes.  If you do need to make changes it would make the most sense to touch the code that calls the flash API.

    Flash Address Range F28334 F28335
    0x300000-0x307FFF(32K) NA Sector H
    0x308000-0x30FFFF(32K) NA Sector G
    0x310000-0x317FFF(32K) NA Sector F
    0x318000-3x31FFFF(32K) NA Sector E
    0x320000-0x323FFF(16K) Sector H Sector D
    0x324000-0x327FFF(16K) Sector G
    0x328000-0x32BFFF(16K) Sector F Sector C
    0x32C000-0x32FFFF(16K) Sector E
    0x330000-0x333FFF(16K) Sector D Sector B
    0x334000-0x337FFF(16K) Sector C
    0x338000-0x33BFFF(16K) Sector B Sector A
    0x33C000-0x33FF7F(16K) Sector A