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TM4C129XNCZAD: TM4C129 and SDRAM alternative

Marco Crivellari
Intellectual 995 points

Part Number: TM4C129XNCZAD
Other Parts Discussed in Thread: TIDM-TM4C129XSDRAM

Hello everyone,
It has been a long time since I last posted on this forum, and it is a pleasure to be back. I have always found this community extremely helpful, with an excellent level of technical support.
 
I would like to discuss SDRAM again in relation to the TM4C129. The ESMT M12L64164A-5BIG2Y SDRAM used in our design is now obsolete, and as far as I know, this device has a rather specific operating mode regarding the CAS latency configuration.
 
The SDRAM operates with a CAS latency of 2, and it has proven difficult to find a currently available replacement device with the same characteristic.
 
Could Texas Instruments recommend a compatible alternative to the M12L64164A that can be reliably used with the TM4C129?
 
Any suggestions or experiences would be greatly appreciated.
Thank you in advance.

 

  • 0
    TI__Intellectual 2200 points

    Hello Marco, 

    Glad to have you back here! Regarding a close replacement, one current device that appears to be a very close replacement candidate is the Alliance Memory AS4C4M16SA-6BIN. It provides the same 64-Mbit / 4M × 16 organization, 3.3-V supply, 54-ball 8 mm × 8 mm FBGA package, industrial temperature range, and programmable CAS latency of 2 or 3. Its CL=2 timing supports operation up to 100+ MHz, so operation at the TM4C129's maximum 60-MHz EPI clock is within its timing capability.

    Therefore, I would recommend evaluating the AS4C4M16SA-6BIN first as the closest current replacement candidate for the M12L64164A-5BIG2Y, while validating the device on the hardware before production use.

    Best Regards, 

    Benedict Jojo

  • 0
    Intellectual 995 points

    Hi Jojo,

    is the AS4C4M16SA-6BIN the only alternative?

  • 0 in reply to Marco Crivellari
    TI__Intellectual 2200 points

    Hello Marco, 

    This is not the only alternative. Another one is ISSI IS42S1620D. Our own development kit, TIDM-TM4C129XSDRAM development kit uses this hence this is also an alternative you can validate!

    Regards, 

    Benedict Jojo

  • 0
    Prodigy 200 points

    The CAS latency point is important here, because I would not treat a replacement as compatible simply because the density and bus width match.

    There is actually a very relevant older TI E2E discussion on this exact subject. TI reported successful testing of the ISSI IS42S16320D-7TLI with TM4C129 devices, and the discussion also covers the fixed CAS-latency behavior of the TM4C129 EPI. Interestingly, the original poster later reported successful testing of an EOL CL=2 device's replacement, the Micron MT48LC4M16A2P-6A, which uses CL=3. TI E2E SDRAM compatibility

    There is also a separate TI E2E thread specifically covering the MT48LC4M16A2P-6A with the TM4C129 EPI. TI E2E MT48LC4M16A2P-6A 

    The older TI E2E discussions are particularly useful because they provide some real-world examples of SDRAMs that have been tested with the TM4C129 EPI.

    I would therefore compare the candidate replacement's CAS latency, timing parameters, refresh requirements, organization, and operating voltage against the existing EPI configuration before changing the hardware.

    When evaluating SDRAM replacements, engineers should confirm specifications in the datasheet and use platforms such as Unikeyic to check availability and alternatives.

    The important thing is to verify CAS latency, timing parameters, organization, voltage, and refresh requirements before treating any device as a replacement.

  • 0 in reply to Rebecca Chen
    Intellectual 995 points

    I hope this information is helpful to the entire community.
    I checked the listed part numbers on Silicon Expert, and the results are not very encouraging.

    AS4C4M16SA-6BIN has an estimated EOL of 5 years
    IS42S16320D-7TLI is obsolete
    MT48LC4M16A2P-6A is obsolete
    M12L64164A-5BIG2Y is obsolete

    Unfortunately, I haven't found any other alternatives so far; it seems the best option right now might be the AS4C4M16SA.

    Does anyone else have more detailed information?

    Thanks.