FM24V01 - 128Kb I2C FRAM
5. The master sends Reserved Slave ID 0xF9
6. The Device ID Read can be done, starting
with the 12 manufacturer bits, followed by
the 9 part identification bits, and then the 3
die revision bits.
7. The master ends the Device ID read
sequence by NACKing the last byte, thus
resetting the slave device state machine and
allowing the master to send the STOP
command.
Device ID
The FM24V01 device incorporates a means of
identifying the device by providing three bytes of
data, which are manufacturer, product ID, and die
revision. The Device ID is read-only. It can be
accessed as follows:
1. The master sends a START command.
2. The master sends Reserved Slave ID 0xF8
3. The master sends the I2C-bus slave address
of the slave device it needs to identify. The
last bit is a ‘Don’t care’ value (R/W bit).
Only one device must acknowledge this byte
(the one that has the I2C-bus slave address).
4. The master sends a Re-START command.
Note: The reading of the Device ID can be stopped
anytime by sending a NACK command.
Start
No
Acknowledge
Acknowledge
Address
A
Address
Start
S
By Master
Stop
S
Rsvd Slave ID (F8)
Slave Address
A
Rsvd Slave ID (F9)
A
Data Byte
A
Data Byte
Data
A
Data Byte
1
P
By FM24V01
Acknowledge
Figure 13. Read Device ID
Manufacturer ID
Product ID
Die Rev.
11 10
9
8
7
6
5
4
3
0
2
1
1
0
0
0
8
7
6
5
4
3
2
1
0
2
1
0
Ramtron
Density
Variation
0
0
0
0
0
0
0
0
0
0
0
1
N
0
0
0
0
0
0
0
Figure 14. Manufacturer and Product ID
Density: 01h=128Kb, 02h=256Kb, 03h=512Kb, 04=1Mb
Variation: Product ID bit 4 = S/N, Product ID bit 0 = reserved
The 3-byte hex code for an FM24V01 will be:
0x00 0x41 0x00
Rev. 3.0
Jan. 2012
Page 9 of 14
RAMTRON [ RAMTRON INTERNATIONAL CORPORATION ]
