|W25Q64FVSFIQ||3V 64M-BIT SERIAL FLASH MEMORY WITH DUAL/QUAD SPI & QPI|
|W25Q64FVSFIQ Datasheet PDF : 89 Pages |
6.2.19 Set Burst with Wrap (77h)
In Standard SPI mode, the Set Burst with Wrap (77h) instruction is used in conjunction with “Fast Read
Quad I/O” and “Word Read Quad I/O” instructions to access a fixed length of 8/16/32/64-byte section
within a 256-byte page. Certain applications can benefit from this feature and improve the overall system
code execution performance.
Similar to a Quad I/O instruction, the Set Burst with Wrap instruction is initiated by driving the /CS pin low
and then shifting the instruction code “77h” followed by 24 dummy bits and 8 “Wrap Bits”, W7-0. The
instruction sequence is shown in Figure 18. Wrap bit W7 and the lower nibble W3-0 are not used.
W4 = 0
W4 =1 (DEFAULT)
Wrap Around Wrap Length
Once W6-4 is set by a Set Burst with Wrap instruction, all the following “Fast Read Quad I/O” and “Word
Read Quad I/O” instructions will use the W6-4 setting to access the 8/16/32/64-byte section within any
page. To exit the “Wrap Around” function and return to normal read operation, another Set Burst with
Wrap instruction should be issued to set W4 = 1. The default value of W4 upon power on is 1. In the case
of a system Reset while W4 = 0, it is recommended that the controller issues a Set Burst with Wrap
instruction to reset W4 = 1 prior to any normal Read instructions since W25Q64FV does not have a
hardware Reset Pin.
In QPI mode, the “Burst Read with Wrap (0Ch)” instruction should be used to perform the Read operation
with “Wrap Around” feature. The Wrap Length set by W5-4 in Standard SPI mode is still valid in QPI
mode and can also be re-configured by “Set Read Parameters (C0h)” instruction. Refer to 7.2.38 and
7.2.39 for details.
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Mode 3
X X X X X X w4 X
X X X X X X w5 X
X X X X X X w6 X
Figure 18. Set Burst with Wrap Instruction (SPI Mode only)
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Publication Release Date: October 07, 2013
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