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How to use 4 EEPROMs that have 1 address bit (I2C)

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jeetz_mail

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Hi

I am trying to connect multiple (4) EEPROMs (M24M02) on the I2C lines. The M24M02 has only one address bit. Is there any way or trick that I can use 4 of these as I2C slaves?

Thanks.
 

nandhu015

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Having a quick look at the datasheet, scl and sda lines paralleled and use 4 io pins for E2.

I think there is no need for extra IC
 

jeetz_mail

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Having a quick look at the datasheet, scl and sda lines paralleled and use 4 io pins for E2.

I think there is no need for extra IC
What do you mean by"scl and sda lines paralleled" and "use 4 io lines for e2"? Please elaborate.

- - - Updated - - -

multiplexing ic
This is a feasible idea. Thanks.
 

spudboy488

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"Paralleled" means that the SCL and SDA lines go to all 4 chips. You do not need to multiplex them.

You would then have a separate I/O line that goes to the E2 pin of each memory chip. To talk to a single chip, you will hold the E2 line of that one chip at one logic level while holding the other 3 at the other logic level. Then, by setting bit 3 (the E2 Chip enable bit) of the device select code byte to the same logic level as the one chip you are communication with, that one will be active and the other 3 will ignore the command because the select code doesn't match.
 

jeetz_mail

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"Paralleled" means that the SCL and SDA lines go to all 4 chips. You do not need to multiplex them.

You would then have a separate I/O line that goes to the E2 pin of each memory chip. To talk to a single chip, you will hold the E2 line of that one chip at one logic level while holding the other 3 at the other logic level. Then, by setting bit 3 (the E2 Chip enable bit) of the device select code byte to the same logic level as the one chip you are communication with, that one will be active and the other 3 will ignore the command because the select code doesn't match.
Thanks a bunch. Very nicely explained.
 

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