help for Interface DPRAM with MCU

Discussion in 'Embedded Systems and Microcontrollers' started by dileepchacko, Nov 5, 2008.

  1. dileepchacko

    Thread Starter Active Member

    May 13, 2008
    102
    1
    Hi All

    help me to use the latches or any other technique to interface the Dual port RAM with PIC18F97J60 MCU. The preferable part number of DPRAM is CY7C28V from cypress.
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    With this memory you need to use half of the pins on the chip package. The other half pins are for simultaneous operation of the RAM with another MCU. Connect the address pins of the RAM A0L-A15L or A0R-A15R to some I/O of the MCU and the I/O0L–I/O15L or I/O0R–I/O15R to some other I/O pins of the MCU. If you use A0L-A15L then you have to use I/O0L–I/O15L too or if you use A0R-A15R then you have to use I/O0R–I/O15R. Also, connect the Chip enable, Output enable etc control pins of the RAM to some I/O of the MCU and the rest is a complicated program;)
    Take care that I/O pins of the RAM are output pins so they have low output impedance and if you short them you will destroy the chip. So make sure that the pins of the MCU are programmed as inputs as to have high input impedance and not destroy the RAM and the MCU too. In addition the interrupt flag and busy flag pins are outputs on the RAM so take care.
     
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