3.3V Uniform Sector
Dual and Quad Serial Flash
GD25Q80C
7.11. Quad I/O Fast Read (EBH)
The Quad I/O Fast Read command is similar to the Dual I/O Fast Read command but with the capability to input the
3-byte address (A23-0) and a “Continuous Read Mode” byte and 4-dummy clock 4-bit per clock by IO0, IO1, IO2, IO3, each
bit being latched in during the rising edge of SCLK, then the memory contents are shifted out 4-bit per clock cycle from IO0,
IO1, IO2, IO3. The command sequence is shown in followed Figure 11. 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 Quad Enable
bit (QE) of Status Register (S9) must be set to enable for the Quad I/O Fast read command.
Quad I/O Fast Read with “Continuous Read Mode”
The Quad I/O Fast Read command can further reduce command overhead through setting the “Continuous Read
Mode” bits (M7-0) after the input 3-byte address (A23-A0). If the “Continuous Read Mode” bits (M7-0) =AXH, then the next
Quad I/O Fast Read command (after CS# is raised and then lowered) does not require the EBH command code. The
command sequence is shown in followed Figure 12. If the “Continuous Read Mode” bits (M7-0) are any value other than
AXH, the next command requires the first EBH command code, thus returning to normal operation. A “Continuous Read
Mode” Reset command can be used to reset (M7-0) before issuing normal command.
Figure 11. Quad I/O Fast Read Sequence Diagram (M7-0= 0XH or not AXH)
CS#
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
SCLK
Command
EBH
SI(IO0)
4
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
SO(IO1)
5
6
7
WP#(IO2)
HOLD#(IO3)
A23-16 A15-8 A7-0 M7-0
Dummy
Byte1 Byte2
Figure 12. Quad I/O Fast Read Sequence Diagram (M7-0= AXH)
CS#
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15
SCLK
SI(IO0)
4
0
4
0
4
0
4
0
4
5
6
7
0
1
2
3
4
5
6
7
0
1
2
3
4
SO(IO1)
5
6
7
1
2
3
5
6
7
1
2
3
5
6
7
1
2
3
5
6
7
1
2
3
5
6
7
WP#(IO2)
HOLD#(IO3)
A23-16 A15-8 A7-0 M7-0
Dummy
Byte1 Byte2
22
GILWAY [ GILWAY TECHNICAL LAMP ]
