S25FL008A Meet Spansion Inc., S25FL008A Datasheet - Page 23

• Manufacturer Part Number: S25FL008A
• Description: 8-megabit Cmos 3.0 Volt Flash Memory With 50 Mhz Spi Bus Interface
• Manufacturer: Meet Spansion Inc.

June 29, 2007 S25FL008A_00_B2
9.12.1
Release from Deep Power Down and Read Electronic Signature (RES)
The device features an 8-bit Electronic Signature, which can be read using the RES command. See
Figure 9.13
Signature is not to be confused with the identification data obtained using the RDID command. The device
offers the Electronic Signature so that it can be used with previous devices that offered it; however, the
Electronic Signature should not be used for new designs, which should read the RDID data instead.
After the host system drives CS# low, it must write the RES command followed by 3 dummy bytes to SI (each
bit is latched on SI during the rising edge of SCK). The Electronic Signature is then output on SO; each bit is
shifted out on the falling edge of SCK. The RES operation is terminated by driving CS# high after the
Electronic Signature is read at least once. Additional clock cycles on SCK with CS# low cause the device to
output the Electronic Signature repeatedly.
When CS# is driven high, the device transitions from DP mode to the standby mode after a delay of t
previously described. The RES command always provides access to the Electronic Signature of the device
and can be applied even if DP mode has not been entered.
Any RES command issued while an erase, program, or WRSR operation is in progress not executed, and the
operation continues uninterrupted.
Notes
1. The S25FL008A has a manufacturer ID of 01h, and a device ID consisting of the memory type (02h) and the memory capacity (13h).
2. The S25FL008A has an Electronic Signature ID of 13h.
Status Register
Figure 9.13 Release from Deep Power Down and Read Electronic Signature (RES) Command Sequence
Power Saving
Write Control
SCK
CS#
Operation
SO
Program
SI
Erase
Read
Hi-Z
and
FAST_READ
Table 9.4 on page 23
Command
WREN
WRSR
RDSR
READ
WRDI
RDID
RES
0
DP
SE
BE
PP
1
2
D a t a
Command
3
Read Data Bytes
Read Data Bytes at Higher Speed
Read Identification
Write Enable
Write Disable
Sector Erase
Bulk (Chip) Erase
Page Program
Read from Status Register
Write to Status Register
Deep Power Down
Release from Deep Power Down
Release from Deep Power Down and
Read Electronic Signature
4
5
S h e e t
6
Table 9.4 Command Definitions
for the command sequence and signature value. The Electronic
Description
S25FL008A
7
MSB
23 22 21
8
(Note 1)
9 10
3 Dummy Bytes
(Note 2)
28 29 30 31 32 33 34 35 36 37 38
3
Deep Power-down Mode
2
1
0
Command Code
D8H (1101 1000)
ABH (1010 1011)
ABH (1010 1011)
03H (0000 0011)
0BH (0000 1011)
9FH (1001 1111)
06H (0000 0110)
C7H (1100 0111)
02H (0000 0010)
05H (0000 0101)
B9H (1011 1001)
04H (0000 0100)
01H (0000 0001)
MSB
7
One-Byte
6
5
Electronic ID out
4
3
Address
2
Bytes
3
3
0
0
0
3
0
3
0
0
0
0
0
1
0
Dummy
t
RES
Byte
0
1
0
0
0
0
0
0
0
0
0
0
3
Standby Mode
Data Bytes
1 to 256
RES
1 to ∞
1 to ∞
1 to ∞
1 to ∞
1 to 3
0
0
0
0
1
0
0
, as
23