GD25LQ40xIGx 1.8V Uniform Sector Dual and Quad Serial Flash
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7.6. Read Data Bytes (READ) (03H)
The Read Data Bytes (READ) command is followed by a 3-byte address (A23-A0), each bit being latched-in
during the rising edge of SCLK. Then the memory content, at that address, is shifted out on SO, each bit being
shifted out, at a Max frequency fR, during the falling edge of SCLK. 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. The whole memory can, therefore, be read with a single Read Data Bytes (READ) command. Any Read
Data Bytes (READ) command, while an Erase, Program or Write cycle is in progress, is rejected without having
any effects on the cycle that is in progress.
Figure 7. Read Data Bytes Sequence Diagram
CS#
0
1
2
3
4
5
6
7
8
9 10
28 29 30 31 32 33 34 35 36 37 38 39
SCLK
SI
Command
03H
24-bit address
23 22 21
MSB
3
2
1
0
Data Out1
Data Out2
High-Z
SO
7
6
5
4
3
2
1
0
MSB
7.7. Read Data Bytes at Higher Speed (Fast Read) (0BH)
The Read Data Bytes at Higher Speed (Fast Read) command is for quickly reading data out. It is followed by
a 3-byte address (A23-A0) and a dummy byte, each bit being latched-in during the rising edge of SCLK. Then
the memory content, at that address, is shifted out on SO, each bit being shifted out, at a Max frequency fC,
during the falling edge of SCLK. 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.
Figure 8. Read Data Bytes at Higher Speed Sequence Diagram
Rev.1.0
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