FM24C04B Datasheet, PDF (7/12 Pages) Ramtron International Corporation – 4Kb Serial 5V F-RAM Memory

By Master
Start
Address
No
Acknowledge
S
Slave Address 1 A
Data Byte
1P
By FM24C04B
Acknowledge Data
Figure 7. Current Address Read
FM24C04B
Stop
By Master
Start
Address
S
Slave Address 1 A
Acknowledge
No
Acknowledge
Data Byte
A
Data Byte
1P
Stop
By FM24C04B
Acknowledge
Data
Figure 8. Sequential Read
By Master ^Start
Address
Start
Address
S
Slave Address 0 A
Word Address
AS
Slave Address 1 A
Acknowledge
No
Acknowledge
Stop
Data Byte
A
Data Byte
1P
By FM24C04B
Acknowledge
Data
Figure 9. Selective (Random) Read
Endurance
The FM24C04B internally operates with a read and
restore mechanism. Therefore, endurance cycles are
applied for each read or write cycle. The memory
architecture is based on an array of rows and
columns. Each read or write access causes an
endurance cycle for an entire row. In the FM24C04B,
a row is 64 bits wide. Every 8-byte boundary marks
the beginning of a new row. Endurance can be
optimized by ensuring frequently accessed data is
located in different rows. Regardless, F-RAM read
and write endurance is effectively unlimited at the
1MHz two-wire speed. Even at 3000 accesses per
second to the same row, 10 years time will elapse
before 1 trillion endurance cycles occur.
Rev. 3.0
Jan. 2012
Page 7 of 12