S25FL040A Meet Spansion Inc., S25FL040A Datasheet - Page 18

• Manufacturer Part Number: S25FL040A
• Description: Small Sector For Boot And Parameter Storage 4-megabit Cmos 3.0 Volt Flash Memory With 50 Mhz Spi Bus Interface
• Manufacturer: Meet Spansion Inc.

9.3
18
Read Identification (RDID)
The Read Identification (RDID) command outputs the one-byte manufacturer identification, followed by the
two-byte device identification, to the host system.
JEDEC assigns the manufacturer identification byte; for Spansion devices it is 01h. The device manufacturer
assigns the device identification: the first byte provides the memory type; the second byte indicates the
memory capacity. See
The host system must first select the device by driving CS# low. The RDID command is then written to SI,
and each bit is latched on the rising edge of SCK. The 24-bit device identification data is output from the
memory array on SO at a frequency f
The RDID command sequence is shown in
Driving CS# high after the device identification data has been read at least once terminates the READ_ID
command. Driving CS# high at any time during data output also terminates the RDID operation.
The device rejects any RDID command issued while it is executing a program, erase, or Write Status Register
operation, and continues the operation uninterrupted.
CS#
SCK
S25FL040A
SO
SI
Device
Mode 3
Mode 0
Hi-Z
Figure 9.3 Read Identification (RDID) Command Sequence and Data-Out Sequence
0
1
Table 9.1
2
Command
Sector Type
Bottom Boot
3
Top Boot
Uniform
4
or
Table 9.5
5
SCK
6
S25FL040A
, on the falling edge of SCK.
7
Figure 9.3
Table 9.1 RDID Data
D a t a
MSB
for device ID data.
8
Manufacturer Identification
9
Manufacturer
Information
10 11 12
(1st Byte)
and
S h e e t
01h
Table
13
9.5.
14 15 16
Memory Type
15
(2nd Byte)
14
Device Identification
02h
02h
02h
17 18
S25FL040A_00_B2 July 2, 2007
Device Identification
13
3
28 29 30 31
2
Memory Capacity
1
(3rd Byte)
0
12h
25h
26h