W25Q128FVCIP datasheet(42/97 Pages) WINBOND

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W25Q128FV

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M7-0

/CS

CLK

Mode 0

Mode 3

A23-16

A15-8

A7-0

Byte 1

Byte 2

IOs switch from

Input to Output

Byte 3

Dummy

Figure 24b. Fast Read Quad I/O Instruction (Previous instruction set M5-4 = 10, SPI Mode)

Fast Read Quad I/O with “8/16/32/64-Byte Wrap Around” in Standard SPI mode

The Fast Read Quad I/O instruction can also be used to access a specific portion within a page by issuing

a “Set Burst with Wrap” (77h) command prior to EBh. The “Set Burst with Wrap” (77h) command can

either enable or disable the “Wrap Around” feature for the following EBh commands. When “Wrap

Around” is enabled, the data being accessed can be limited to either an 8, 16, 32 or 64-byte section of a

256-byte page. The output data starts at the initial address specified in the instruction, once it reaches the

ending boundary of the 8/16/32/64-byte section, the output will wrap around to 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 “Set Burst with Wrap” instruction allows three “Wrap Bits”, W6-4 to be set. The W4 bit is used to

enable or disable the “Wrap Around” operation while W6-5 are used to specify the length of the wrap

around section within a page. Refer to section 8.2.24 for detail descriptions.

W25Q128FVCIP Datasheet(PDF) 42 Page - Winbond