Extending the RAM memory of a PIC microcontroller

Dilshan designed a RAM memory extender for PIC microcontrollers. The circuit uses some logic ICs and SRAM memory modules to extend the data memory of a PIC. The designer provided source code for this project written for the MikroC compiler.

With this given schematic user may be able to address RAM space up to 192KB. But this can be extended up to 448KB by adding more SRAM modules to the system. In this given setup we use 24512 – 64K x 8 CMOS SRAMs as a memory modules. 74HC373 latch is used as 8bit to 16bit address extender and 74HC138 demultiplexer is used as memory bank selector.

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  1. The diagram reminds me of 8051 using no internal flash memories for storing you program. Ohhh that 373 latch and the 138 mux.

  2. Nice project, and a question: did you ever thinking about PSRAMs too? They aren’t Kbytes but Mbytes! The only annoying thing is the Micron’s VFBGA socket (they aren’t in pruduction with TSOP at this moment).

    If you ever gonna drop psrams on breakout board, plz let me know about that project. Thx.

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