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GD25Q128CXIGX Datasheet, PDF (29/69 Pages) ELM Electronics – 3.3V Uniform Sector Dual and Quad Serial Flash | |||
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GD25Q128CxIGx 3.3V Uniform Sector Dual and Quad Serial Flash
http://www.elm-tech.com
Quad I/O Word Fast Read with â8/16/32/64-Byte Wrap Aroundâ in Standard SPI mode
The Quad I/O Word Fast Read command can be used to access a specific portion within a page by issuing âSet
Burst with Wrapâ (77H) commands prior to E7H. The âSet Burst with Wrapâ (77H) command can either enable
or disable the âWrap Aroundâ feature for the following E7H commands. When âWrap Aroundâ is enabled, the
data being accessed can be limited to either an 8/16/32/64-byte section of a 256-byte page. The output data
starts at the initial address specified in the command, once it reaches the ending boundary of the 8/16/32/64-byte
section, the output will wrap around the beginning boundary automatically until CS# is pulled high to terminate
the command.
The Burst with Wrap feature allows applications that use cache to quickly fetch a critical address and then fill
the cache afterwards within a fixed length (8/16/32/64-byte) of data without issuing multiple read commands.
The âSet Burst with Wrapâ command allows three âWrap Bitsâ W6-W4 to be set. The W4 bit is used to enable
or disable the âWrap Aroundâ operation while W6-W5 is used to specify the length of the wrap around section
within a page.
7.13. Set Burst with Wrap (77H)
The Set Burst with Wrap command is used in conjunction with âQuad I/O Fast Readâ and âQuad I/O Word
Fast Readâ command to access a fixed length of 8/16/32/64-byte section within a 256-byte page, in standard SPI
mode. The Set Burst with Wrap command sequence: CS# goes low â Send Set Burst with Wrap command â
Send 24 dummy bits â Send 8 bits âWrap bitsâ â CS# goes high.
W6, W5
W4=0
Wrap Around
Wrap Length
W4=1 (default)
Wrap Around
Wrap Length
0, 0
Yes
8-byte
No
N/A
0, 1
Yes
16-byte
No
N/A
1, 0
Yes
32-byte
No
N/A
1, 1
Yes
64-byte
No
N/A
If the W6-W4 bits are set by the Set Burst with Wrap command, all the following âQuad I/O Fast Readâ and
âQuad I/O Word Fast Readâ command will use the W6-W4 setting to access the 8/16/32/64-byte section within
any page. To exit the âWrap Aroundâ function and return to normal read operation, another Set Burst with Wrap
command should be issued to set W4=1. In QPI mode, the âBurst Read with Wrap (0CH)â command should be
used to perform the Read Operation with âWrap Aroundâ feature. The Wrap Length set by W5-W6 in Standard
SPI mode is still valid in QPI mode and can also be re-configured by âSet Read Parameters (C0H) command.
Figure 15. Set Burst with Wrap Sequence Diagram
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)
Command
77H
xxxxxx4x
xxxxxx5x
xxxxxx6x
xxxxxxxx
W6-W4
69 - 29
Rev.1.2
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