External i2c eeprom 24c64

[nis2311]

I am interfacing external EEPROM 24C64 to my controller. So it has 64K (8192 x 8) memory space. It is working fine upto address 8159 (decimal), it is not working from 8160. Instead of writing in 8160 address it is writing in 0 address. So in the datasheet also they mentioned first word address is 5 bits only and second word address is 8 bit. My query is, how can I save a data in the address like 0XFFFF or 0X2F00. how can i access these address to save the data................help me to solve this problem............

 

[betwixt]

The '64' refers to kilo BITS so being 8 bits wide, there are only 8192 available addresses. That means the address range is from 0x0000 to 0x1FFF (0 to 8191 in decimal). To include address 0xFFFF you would need a 24C512.

Brian.

 

[FvM]

The memory has 8192 memory locations, hex address range 0x0000 to 0x1FFF, 13 address bits, what's wrong with it?

it is not working from 8160. Instead of writing in 8160 address it is writing in 0 address.

I can just guess that you are writing beyond address 8195 (0x1FFF) rather than 8160.

 

[KlausST]

Hi,

Just a guess: Maybe it has to do with 32 byte page size.

Klaus

 

[paulfjujo]

hello,

With Hardware connexions pins A0,A1,A2 on EEPROM , you can shift the adress
A0=> A13
A1 =>A14
A2=> A15

so with this 3 pins to 1
1110 0000 0000 0000
E0000 to FFFF

or any other combinaison

also they mentioned first word address is 5 bits only and second word address is 8 bit.

8191
1 F F F
1 1111 1111 1111

you can handle the eeprom Byte per Byte or Page per Page
so 256 pages of 32 bytes
1111 1111 11111

 

[andre_luis]

how can I save a data in the address like 0XFFFF or 0X2F00

In fact, according to paulfjujo approach, to be able to save data within this range you need at least 6 memory chips of that device [(0xFFFF-0x2FFF)/8192] arranged in a straight bank along the above address, part handled within I2C protocol (A₀:A₁₂), part handled at the 24C64 external pins (A₁₃:A₁₅).