D a t a S h e e t ( P r e l i m i n a r y )
The RDID command sequence is shown in Figure 9.3 and Table 9.5.
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.
Figure 9.3 Read Identification (RDID) Command Sequence and Data-Out Sequence
CS#
1
28
30
29
31
2
3
4
5
6
18
17
Mode 3
Mode 0
0
7
14 15 16
8
9
10 11
13
12
SCK
SI
Command
Manufacturer Identification
Device Identification
Hi-Z
0
1
3
2
14
13
SO
15
MSB
Table 9.1 READ_ID Data
Data
Bottom
Boot
Address
00000h
00001h
Uniform
01h
Top Boot
01h
Manufacturer Identification
Device Identification (Memory Capacity)
01h
26h
12h
25h
9.4
Read Identification (Read_ID) [RDID Alternate]
The READ_ID instruction provides the S25FL040A manufacturer and device information. This command
should be used as default device identification when multiple versions of SPI Serial Flash devices are used in
a design.
The device information can be read from by writing the 8-bit command (90H) follwed by address bits.
Following the READ_ID instruction, the manufacturer’s ID is located at address 00000H and the device ID
(Memory Capacity) is located at address 00001H. Once the device is in READ_ID mode, the manufacturer’s
and device ID output data toggles between address 00000H and 00001H until CE# is driven high.
16
S25FL040A
S25FL040A_00_B0 August 31, 2006
SPANSION [ SPANSION ]
