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Help me write program to 24LC640 EEPROM using MSP430F449 SPI bus

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Member level 4
Jun 30, 2006
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Dear all,
I am new to write program to 24LC640 EEPROM using MSP430F449 SPI bus. So pls help me how to do this by examples or any related links. Thanks in advance.

Re: Help me to WR EEROM

Basically, you must learn tihs EEPROM's Serial Interface.

This have simply interface...
Commands ;

READ 0000 0011 Read data from memory array beginning at selected address
WRITE 0000 0010 Write data to memory array beginning at selected address
WREN 0000 0110 Set the write enable latch (enable write operations)
WRDI 0000 0100 Reset the write enable latch (disable write operations)
RDSR 0000 0101 Read status register
WRSR 0000 0001 Write status register

Read Sequence
The part is selected by pulling CS low. The 8-bit read
instruction is transmitted to the 25xx640 followed by the
16-bit address with the three MSB’s of the address
being don’t care bits. After the correct read instruction
and address are sent, the data stored in the memory at
the selected address is shifted out on the SO pin. The
data stored in the memory at the next address can be
read sequentially by continuing to provide clock pulses.
The internal address pointer is automatically incremented
to the next higher address after each byte of
data is shifted out. When the highest address is
reached (1FFFh), the address counter rolls over to
address 0000h allowing the read cycle to be continued
indefinitely. The read operation is terminated by raising
the CS pin

Prior to any attempt to write data to the 25xx640 array
or status register, the write enable latch must be set by
issuing the WREN instruction (Figure 3-4). This is
done by setting CS low and then clocking out the
proper instruction into the 25xx640. After all eight bits
of the instruction are transmitted, the CS must be
brought high to set the write enable latch. If the write
operation is initiated immediately after the WREN
instruction without CS being brought high, the data will
not be written to the array because the write enable
latch will not have been properly set.
Once the write enable latch is set, the user may proceed
by setting the CS low, issuing a write instruction,
followed by the address, and then the data to be written.
Up to 32 bytes of data can be sent to the 25xx640
before a write cycle is necessary. The only restriction is
that all of the bytes must reside in the same page. A
page address begins with XXX0 0000 and ends with
XXX1 1111. If the internal address counter reaches
XXX1 1111 and the clock continues, the counter will
roll back to the first address of the page and overwrite
any data in the page that may have been written.
For the data to be actually written to the array, the CS
must be brought high after the least significant bit (D0)
of the nth data byte has been clocked in. If CS is
brought high at any other time, the write operation will
not be completed. Refer to Figure 3-2 and Figure 3-3
for more detailed illustrations on the byte write
sequence and the page write sequence respectively.
While the write is in progress, the status register may
be read to check the status of the WPEN, WIP, WEL,
BP1, and BP0 bits. A read attempt of a
memory array location will not be possible during a
write cycle. When the write cycle is completed, the
write enable latch is reset.

:arrow:All information in this data sheet , please read ..

**broken link removed**
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