n25q256 Numonyx, n25q256 Datasheet - Page 75

• Manufacturer Part Number: n25q256
• Description: 256-mbit 3 V, Multiple I/o, 4-kbyte Subsector Erase, Xip Enabled, Serial Flash Memory With 108 Mhz Spi Bus Interface
• Manufacturer: Numonyx

N25Q256 - 3 V
9.1.11
Note:
DQ0
DQ1
DQ3
DQ2
C
S
Mode 3
Mode 0
Quad Output Fast Read
The Quad Output Fast Read (QOFR) instruction is very similar to the Dual Output Fast
Read (DOFR) instruction, except that the data are shifted out on four pins (pin DQ0, pin
DQ1, pin W/VPP/DQ2 and pin HOLD/DQ3 (1) instead of only two. Outputting the data on
four pins instead of one doubles the data transfer bandwidth compared to the Dual Output
Fast Read (DOFR) instruction.
The device is first selected by driving Chip Select (S) Low. The instruction code for the Quad
Output Fast Read instruction is followed by a 3-byte address (A23-A0) and a dummy byte,
each bit being latched-in during the rising edge of Serial Clock (C). Then the memory
contents, at that address, are shifted out on pin DQ0, pin DQ1, pin W/VPP/DQ2 and pin
HOLD/DQ3 (1) at a maximum frequency fC, during the falling edge of Serial Clock (C).
The first byte addressed can be at any location. The address is automatically incremented
to the next higher address after each byte of data is shifted out on pin DQ0, pin DQ1, pin
W/VPP/DQ2 and pin HOLD/DQ3 (1). The whole memory can, therefore, be read with a
single Quad Output Fast Read (QOFR) instruction. When the highest address is reached,
the address counter rolls over to 00000000h, so that the read sequence can be continued
indefinitely.
If 4-byte address mode is enabled, the device uses a 32-bit address as explained and
shown in
Reset functionality is available instead of Hold in devices with a dedicated part number. See
Section 16: Ordering
Figure 28. Quad Output Fast Read instruction sequence
0
Don’t Care
‘1’
Don’t Care
Section 5.1.2: 4 Byte Address Mode on page 25
1
2
Instruction
3
4
information.
5
6
7
23 22 21 20
8
9 10 11
24-bit Address
Micron Technology, Inc., reserves the right to change products or specifications without notice.
1
30
31 32
0
Dummy
39
©2010 Micron Technology, Inc. All rights reserved.
40
Byte 1 Byte 2
6
7
4
5
IO switches from Input to Output
41
2
3
0
1
42
6
7
4
5
43
2
3
0
1
5
6
7
4
Instructions
75/186