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Accessing external I2C EEPROM with Cypress EZ-USB dev kit

Started by galapogos October 7, 2007
Hi,

I have the Cypress FX2LP development kit, and according to the manual,
I can select either large EEPROM(Microchip 24LC128) for simulation or
small EEPROM(Microchip 24LC00) for debugging. Since I'm still in my
development stage, I'm debugging the firmware, so I'm choosing small
EEPROM. The problem is that I wish to address another I2C EEPROM chip
in my firmware, a Microchip 24AA08. According to the 24LCC00 and
24AA08 datasheets, it would appear that neither of these EEPROM chips
can work with any other EEPROM chip, i.e. they both take over control
of the I2C bus as far as EEPROM devices go, since the A0, A1 and A2
pins are all ignored/don't cares. Hence if I try to access the EEPROM
I2C device address of 1010, it will address both of them at once(I
think?), since the lower byte is ignored.

Is there any way of getting around this?

Hi galapogos,

You can always choose to ignore the on-chip I2C interface, and
implement one on the general-purpose pins (in software).  Then you can
wire the microchip memory to the software interface, and all other I2C
devices to the hardware interface.

Regards,
Marc