25LC512
DS20005265A-page 18 2014 Microchip Technology Inc.
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.
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 clocked in, the 8-bit
Electronic Signature is clocked out on the SO pin.
After the signature has been read out at least once,
the sequence can be terminated by driving CS
high.
After a delay of T
REL, 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
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, as shown in Figure 2-13.
FIGURE 2-13: RELEASE FROM DEEP POWER-DOWN
SO
SI
SCK
CS
0 2345671
01101011
Instruction
High-Impedance
T
REL
SI
SCK
CS
0 234567891011 21222324252627282930311
01101011
15 14 13 12 210
76543210
Instruction 16-bit Address
Electronic Signature Out
High-Impedance
0 1010010
Manufacturer’s ID = 0x29
