S25FL004K Meet Spansion Inc., S25FL004K Datasheet - Page 31

• Manufacturer Part Number: S25FL004K
• Description: 4-mbit / 8-mbit / 16-mbit Cmos 3.0 Volt Flash Memory With 104-mhz Spi Serial Peripheral Interface Multi I/o Bus
• Manufacturer: Meet Spansion Inc.

7.8
July 14, 2011 S25FL004K-016K_00_02
Fast Read Dual Output (3Bh)
The Fast Read Dual Output (3Bh) instruction is similar to the standard Fast Read (0Bh) instruction except that
data is output on two pins; IO0 and IO1. This allows data to be transferred from the S25FL004K/S25FL008K/
S25FL016K at twice the rate of standard SPI devices. The Fast Read Dual Output instruction is ideal for
quickly downloading code from Flash to RAM upon power-up or for applications that cache code-segments to
RAM for execution.
Similar to the Fast Read instruction, the Fast Read Dual Output instruction can operate at the highest
possible frequency of F
eight “dummy” clocks after the 24-bit address as shown in
internal circuits additional time for setting up the initial address. The input data during the dummy clocks is
“don’t care”. However, the IO0 pin should be high-impedance prior to the falling edge of the first data out
clock.
CLK
CLK
IO0
IO1
IO0
CS
CS
IO1
= MSB
Mode 3
Mode 0
32
0
33 34 35
Dummy Clocks
1
Figure 7.8 Fast Read Dual Output Instruction Sequence Diagram
Instruction (3Bh)
2
R
.
D a t a
(See AC Electrical Characteristics on page
3
36 37
S25FL004K / S25FL008K / S25FL016K
4
5
38 39 40
S h e e t
6
7
6
7
Data Out 1
23
4
5
8
41
IO_0 Switches from Input to Output
22 21
2
3
9
42
24-Bit Address
10
1
0
43 44 45 46 47
7
6
3
Data Out 2
28 29
Figure
4
5
2
3
2
1
30 31
7.8. The dummy clocks allow the device's
0
1
0
64.) This is accomplished by adding
6
7
48 49 50
Data Out 3
4
5
2
3
0
1
51 52 53
6
7
Data Out 4
4
5
2
3
54 55
0
1
6
7
31