FM25640-G Ramtron, FM25640-G Datasheet - Page 8

• Manufacturer Part Number: FM25640-G
• Description: IC, FRAM, 64KBIT, 5MHZ, SOIC-8
• Manufacturer: Ramtron

Specifications of FM25640-G

• Memory Size: 64Kbit
• Memory Configuration: 8K X 8
• Ic Interface Type: Serial, SPI
• Supply Voltage Range: 4.5V To 5.5V
• Memory Case Style: SOIC
• No. Of Pins: 8
• Operating Temperature Range: -40°C To +85°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Endurance
Internally, a FRAM operates with a read and restore
mechanism
endurance cycles are applied for each access: read or
write. The FRAM architecture is based on an array of
rows and columns. Each access causes a cycle for an
entire row. Therefore, data locations targeted for
substantially differing numbers of cycles should not
Rev. 3.2
Feb. 2011
SCK
SO
CS
SCK
SI
CS
SO
SI
0
0
0
0
similar
0
1
0
1
0
2
0
2
op-code
0
3
op-code
0
to
3
0
4
0
4
a
0
5
0
5
1
DRAM.
6
1
6
0
7
1
MSB
7
MSB
X
0
X
0
Therefore,
X
1
Figure 10. Memory Read
Figure 9. Memory Write
X
1
X 12 11 10
2
X 12 11 10
13-bit Address
2
3
13-bit Address
3
4
4
5
5
be located within the same row. In the FM25640,
there are 2048 rows each 32 bits wide. Each 4 bytes
in the address mark the beginning of a new row.
Regardless, FRAM read and write endurance is
effectively unlimited at the 5MHz clock speed. Even
at 2000 accesses per second to the same row, 15
years time will elapse before 10
occur.
4
3
4
3
3
4
3
4
2
5
2
5
1
6
LSB MSB
1
6
0
LSB MSB
7
0
7
7
0
7
0
6
1
6
1
5
2
Data
5
2
4
3
Data
4
3
12
3
4
endurance cycles
3
4
2
5
2
5
1
6
FM25640
1
6
LSB
0
7
LSB
8 of 13
0
7