Upgrading the 4-Meg (CY7C0852V/AV) Dual-Port to a 9-Meg (CY7C0853V/AV) Dual-Port

Question: What are the pin considerations while upgrading from a 4-Meg (CY7C0852V/AV) Dual-Port to a 9-Meg (CY7C0853V/AV) Dual-Port?

 

Answer:

The CY7C0852V/AV and CY7C0853V/AV are 4 - Meg and 9 - Meg synchronous dual ported SRAMs. Both these devices are available in 172-BGA packages and hence one can easily upgraded from a 4-Meg CY7C0852V/AV to a 9-Meg CY7C0853V/AV without having to respin the board. The upgrade only requires the use of a few zero-ohm resistors to change the configuration of a few pins . The pins to be considered for such an upgrade are discussed in the table below:

 

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
  Pinout Differences
    0852 ball     0852 Name    0853 Name    CY7C0852V/AV    CY7C0853V/AV
    A12    /CNTINTR    N/C    Series Zero-Ohm Resistor    No Connect
    A3    /CNTINTL    N/C    Series Zero-Ohm Resistor    No Connect
    C1     NC    A17L    No Connect    Series Zero-Ohm Resistor
    C14    NC    A17R    No Connect    Series Zero-Ohm Resistor
    The following pins require two zero ohm resistors connected as specified in the table. One zero-ohm resistor should be in series with these pins to their respective control signals. The other zero-ohm resistor
    should lead from these pins to Vdd/Vss.
    E3    CE1L    Vdd    Series Zero-Ohm Resistor    Zero-Ohm to Vdd
    E12    CE1R    Vdd    Series Zero-Ohm Resistor    Zero-Ohm to Vdd
    G4    /CE0L    Vss    Series Zero-Ohm Resistor    Zero-Ohm to Vss
    G11    /CE0R    Vss    Series Zero-Ohm Resistor    Zero-Ohm to Vss
    J4    /ADSL    Vss    Series Zero-Ohm Resistor    Zero-Ohm to Vss
    J11    /ADSR    Vss    Series Zero-Ohm Resistor    Zero-Ohm to Vss
    K4    /CNTRSTL    Vdd    Series Zero-Ohm Resistor    Zero-Ohm to Vdd
    K11    /CNTRSTR    Vdd    Series Zero-Ohm Resistor    Zero-Ohm to Vdd
    L1    CNT/MSKbL    Vdd    Series Zero-Ohm Resistor    Zero-Ohm to Vdd
    L14    CNT/MSKbR    Vdd    Series Zero-Ohm Resistor    Zero-Ohm to Vdd
    L3    /CNTENL    Vss    Series Zero-Ohm Resistor    Zero-Ohm to Vss
    L12    /CNTENR    Vss    Series Zero-Ohm Resistor    Zero-Ohm to Vss