P89c51rd2 Ram Address problem

Dear all,
My project is using P89c51rd2 added an external ram(8k).
Accroding to the data sheet
the memory model of P89c51rd2 is that:

0-7f lower 128 byte
80-ff Higner 128 byte
100-3fff ERAM

-----------------------------
Extrnal 8K ram from 0000~1FFF.
------------------------------

if i connected the external ram to P89c51rd2
What is the starting address of the External RAM?

Will the Eram and external ram address overall together


if i want to use the XBYTE[] to acess the external ram address

How can i do it?

Parents
  • Hi,

    I am a beginner using Keil C51 complier. I have the same question:

    My program works with an xdata array within the 1K on-chip RAM [ERAM] and now I have 32K static RAM (62256) board connected to the P89C51RD2. When I declare the SAME xdata array to a larger size that goes beyond the 1K on-chip ERAM, the program can't work.

    Any advice as to how I can access external RAM?

    Kind regards,
    Simon

    PS Hi Raul, do you have an answer for your question now? Your reply is very much appreciated. Thanking you in advance.

Reply
  • Hi,

    I am a beginner using Keil C51 complier. I have the same question:

    My program works with an xdata array within the 1K on-chip RAM [ERAM] and now I have 32K static RAM (62256) board connected to the P89C51RD2. When I declare the SAME xdata array to a larger size that goes beyond the 1K on-chip ERAM, the program can't work.

    Any advice as to how I can access external RAM?

    Kind regards,
    Simon

    PS Hi Raul, do you have an answer for your question now? Your reply is very much appreciated. Thanking you in advance.

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