D a t a S h e e t ( P r e l i m i n a r y )
9.2
Read Data Bytes at Higher Speed (FAST_READ)
The FAST_READ command reads data from the memory array at the frequency (fSCK) presented at the SCK
input, with a maximum speed of 50 MHz. The host system must first select the device by driving CS# low. The
FAST_READ command is then written to SI, followed by a 3-byte address (A23-A0) and a dummy byte. Each
bit is latched on the rising edge of SCK. The memory array data, at that address, are output serially on SO at
a frequency fSCK, on the falling edge of SCK.
The FAST_READ command sequence is shown in Figure 9.2 and Table 9.4. The first byte specified can be at
any location. The device automatically increments to the next higher address after each byte of data is output.
The entire memory array can therefore be read with a single FAST_READ command. When the highest
address is reached, the address counter reverts to 00000h, allowing the read sequence to continue
indefinitely.
The FAST_READ command is terminated by driving CS# high at any time during data output. The device
rejects any FAST_READ command issued while it is executing a program, erase, or Write Status Register
operation, and continues the operation uninterrupted.
Figure 9.2 Read Data Bytes at Higher Speed (FAST_READ) Command Sequence
CS#
33
0
1
2
5
6
7
8
9
29 30
32
38 39 40 41
44 45 46
42 43
Mode 3
31
34 35 36 37
3
4
10
28
47
SCK
Mode 0
24-Bit Address
Dummy Byte
Command
23
3
2
22 21
1
0
6
5
4
2
0
1
7
3
SI
Hi-Z
3
7
6
4
2
1
0
5
7
SO
MSB
MSB
DATA OUT 1
DATA OUT 2
September 1, 2006 S25FL032A_00_C0
S25FL032A
15
SPANSION [ SPANSION ]
