S25FL004A Meet Spansion Inc., S25FL004A Datasheet - Page 24

• Manufacturer Part Number: S25FL004A
• Description: 4-megabit Cmos 3.0 Volt Flash Memory With 50 Mhz Spi Bus Interface
• Manufacturer: Meet Spansion Inc.

24
9.12.1
SCK
CS#
SO
SI
Release from Deep Power Down and Read Electronic Signature (RES)
Hi-Z
The device features an 8-bit Electronic Signature, which can be read using the RES command. See
Figure 9.13 on page 24
Electronic 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 S25FL004A has a manufacturer ID of 01h, and a device ID consisting of the memory type (02h) and the memory capacity (12h).
Status Register
Power Saving
Write Control
Operation
Program
Erase
Read
0
Figure 9.13 Release from Deep Power Down and Read Electronic Signature (RES)
1
FAST_READ
Command
2
WREN
WRSR
Command
RDSR
READ
WRDI
RDID
RES
SE
BE
PP
DP
3
4
and
5
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
Table 9.4 on page 24
6
7
MSB
23 22 21
8
Table 9.4 Command Definitions
Description
9 10
S25FL004A
3 Dummy Bytes
(Note 1)
Command Sequence
D a t a
28 29 30 31 32 33 34 35 36 37 38
(Note 2)
3 2
Deep Power-down Mode
for the command sequence and signature value. The
1
S h e e t
0
MSB
7
ABH (1010 1011)
ABH (1010 1011)
Command Code
0BH (0000 1011)
9FH (1001 1111)
D8H (1101 1000)
C7H (1100 0111)
B9H (1011 1001)
03H (0000 0011)
06H (0000 0110)
04H (0000 0100)
02H (0000 0010)
05H (0000 0101)
01H (0000 0001)
6
One-Byte
5
Electronic ID out
4
3
2
S25FL004A_00_B3 July 9, 2007
Address
1
Bytes
3
0
0
3
3
0
0
0
0
3
0
0
0
0
t
RES
Dummy
Byte
0
1
0
0
0
0
0
0
0
0
0
0
3
Standby Mode
RES
1 to 256
Bytes
1 to ∞
1 to ∞
1 to ∞
1 to ∞
1 to 3
Data
0
0
0
0
1
0
0
, as