GD25Q80 Datasheet, PDF (21/49 Pages) ELM Electronics – 3.3V Uniform Sector Dual and Quad Serial Flash

GD25Q80CxIGx 3.3V Uniform Sector Dual and Quad Serial Flash
7.11. Quad I/O Fast Read (EBH)
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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
Figure13. 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 Figure14. 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 13. Quad I/O Fast Read Sequence Diagram (M7-0 = 0XH or not AXH)
CS#
SCLK
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
SI(IO0)
SO(IO1)
WP#(IO2)
HOLD#(IO3)
Command
EBH
40404040
4040 4
51515151
5151 5
62626262
6262 6
73737373
A23-16 A15-8 A7-0 M7-0
Dummy
7373 7
Byte1 Byte2
Figure 14. Quad I/O Fast Read Sequence Diagram (M7-0 = AXH)
CS#
SCLK
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
SI(IO0)
SO(IO1)
WP#(IO2)
HOLD#(IO3)
40404040
4040 4
51515151
5151 5
62626262
6262 6
73737373
A23-16 A15-8 A7-0 M7-0
Dummy
7373 7
Byte1 Byte2
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Rev.1.0