w25q64dw Winbond Electronics Corp America, w25q64dw Datasheet - Page 31

• Manufacturer Part Number: w25q64dw
• Description: 1.8v 64m-bit Serial Flash Memory With Dual/quad Spi & Qpi
• Manufacturer: Winbond Electronics Corp America

10.2.14 Fast Read Quad Output (6Bh)
The Fast Read Quad Output (6Bh) instruction is similar to the Fast Read Dual Output (3Bh) instruction
except that data is output on four pins, IO
executed before the device will accept the Fast Read Quad Output Instruction (Status Register bit QE
must equal 1). The Fast Read Quad Output Instruction allows data to be transferred from the
W25Q64DW at four times the rate of standard SPI devices.
The Fast Read Quad Output instruction can operate at the highest possible frequency of F
Electrical Characteristics). This is accomplished by adding eight “dummy” clocks after the 24-bit address
as shown in Figure 13. The dummy clocks allow the device's internal circuits additional time for setting up
the initial address. The input data during the dummy clocks is “don’t care”. However, the IO pins should
be high-impedance prior to the falling edge of the first data out clock.
CLK
CLK
/CS
/CS
IO
IO
IO
IO
IO
IO
IO
IO
0
1
2
3
0
1
2
3
Mode 3
Mode 0
0
31
*
= MSB
32
Figure 13. Fast Read Quad Output Instruction (SPI Mode only)
33
0
High Impedance
High Impedance
High Impedance
Dummy Clocks
34
1
35
Instruction (6Bh)
2
36
0
, IO
3
37
1
4
, IO
High Impedance
High Impedance
High Impedance
38
- 31 -
2
5
, and IO
39
6
Byte 1
4
5
6
7
40
7
3
. A Quad enable of Status Register-2 must be
0
1
2
3
23
41
*
8
IO
Input to Output
Byte 2
4
5
6
7
22
42
Publication Release Date: January 13, 2011
0
9
switches from
0
1
2
3
21
43
10
24-Bit Address
Byte 3
4
5
6
7
44
0
1
2
3
45
3
28
Byte 4
4
5
6
7
46
2
29
Preliminary - Revision C
W25Q64DW
0
1
2
3
47
1
30
4
5
6
7
0
31
R
(see AC