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TM4C1299KCZAD: SRAM connection by EPI HB16 mode, can support up to 8pcs SRAM?

Chia Hung Lin
Prodigy 160 points
Part Number: TM4C1299KCZAD

We would like to use EPI Host Bus 16 mode(ADMUX) to connect SRAM(1Mbx16). Is it possible to connect 8pcs SRAM at the same time?

From my understanding, all signals are connected together except CS(chip select) pin. Please help to check it.

  • 0
    TI__Guru**** 160485 points

    Hi Chia,

     According to the datasheet only 4 chip selects are supported. Below is the excerpt from the datasheet.

    Host-Bus 8 and Host-Bus 16 modes are very configurable. The user has the ability to connect 1,2,

    or 4 external devices to the EPI signals, as well as control whether byte select signals are provided

    in HB16 mode.

  • 0 in reply to Charles Tsai
    Guru 117850 points

    Charles well documented - and explained.

    Yet - if poster (or others) REALLY REQUIRE "added chip selects" is it NOT POSSIBLE to route, "Each of the four existing "CSn" signals into a, "Data Mux/Selector chip" - such that  "1 of 2 SRAMs" may be individually selected.     (such appears "reasonable" (minus required  EPI "fan-out"))

    Now poster wrote, "Connect 8 pcs SRAM - at the same time."     I doubt that's (any) issue - as "one and only one SRAM" ... is  (only & ever) accessed - at any one time!  

    I would suspect that one of the EPI's (unused) signals may serve to "Switch the Mux/Selector bank" IC (or ICs).     If unavailable - then a "spare" MCU GPIO" may serve that role...

    Note that neither firm/I employ the '129 - yet this EXACT METHOD was employed in conjunction w/an FPGA - with GREAT SUCCESS - years past...