25AA512/25LC512
Release from Deep Power-Down mode and Read
Electronic Signature is entered by driving CS low,
followed by the RDID instruction code (Figure 2-12)
and then a dummy address of 16 bits (A15-A0). After
the last bit of the dummy address is clock in, the 8-bit
Electronic Signature is clocked out on the SO pin.
2.12 RELEASE FROM DEEP POWER-
DOWN AND READ ELECTRONIC
SIGNATURE
Once the device has entered Deep Power-Down
mode all instructions are ignored except the Release
from Deep Power-down and Read Electronic Signa-
ture command. This command can also be used when
the device is not in Deep power-down to read the
electronic signature out on the SO pin unless another
command is being executed such as Erase, Program
or Write Status Register.
After the signature has been read out at least once,
the sequence can be terminated by driving CS high.
The device will then return to Standby mode and will
wait to be selected so it can be given new instructions.
If additional clock cycles are sent after the electronic
signature has been read once, it will continue to output
the signature on the SO line until the sequence is
terminated.
FIGURE 2-12:
RELEASE FROM DEEP POWER-DOWN AND READ ELECTRONIC SIGNATURE
CS
0
1
2
3
4
5
6
7
8
9 10 11
21 22 23 24 25 26 27 28 29 30 31
SCK
Instruction
16-bit Address
15 14 13 12
1
0
1
0
1
0
1
1
2
1
0
SI
Electronic Signature Out
High-Impedance
7
6
5
4
3
2
1
0
SO
0
0
1
0
1
0
0
1
Manufacturer’s ID = 0x29
Driving CS high after the 8-bit RDID command but before the Electronic Signature has been transmitted will still ensure
the device will be taken out of Deep Power-Down mode. However, there is a delay TREL that occurs before the device
returns to Standby mode (ICCS), as shown in Figure 2-13.
FIGURE 2-13:
RELEASE FROM DEEP POWER-DOWN AND READ ELECTRONIC SIGNATURE
CS
TREL
0
1
2
3
4
5
6
7
SCK
SI
Instruction
1
0
1
0
1
0
1
1
High-Impedance
SO
DS22021B-page 18
Preliminary
© 2007 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
