W25Q256JVEIQ-TR Datasheet, PDF (49/92 Pages) Winbond – 3V 256M-BIT SERIAL FLASH MEMORY WITH DUAL/QUAD SPI

W25Q256JV
8.2.21 Fast Read Quad I/O with 4-Byte Address (ECh)
The Fast Read Quad I/O with 4-Byte Address instruction is similar to the Fast Read Dual I/O instruction
except that it requires 32-bit address instead of 24-bit address. No matter the device is operating in 3-Byte
Address Mode or 4-byte Address Mode, the Fast Read Quad I/O with 4-Byte Address instruction will
always require 32-bit address to access the entire 256Mb memory.
The Fast Read Quad I/O with 4-Byte Address (ECh) instruction is only supported in Standard SPI mode.
/CS
CLK
Mode 3
Mode 0
IO0
IO1
IO2
IO3
0123456789
14 15 16 17 18 19 20 21 22 23 24 25
Instruction (ECh)
32-Bit Address
M7-0 Dummy Dummy
IOs switch from
Input to Output
28 24
4040
40404
29 25
5151
51515
30 26
6262
62626
31 27
7373
73
Byte 1
73
Byte 2
7
Byte 3
Figure 28. Fast Read Quad I/O w/ 4-Byte Addr. (M7-M0 should be set to FFh)
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 ECh. The “Set Burst with Wrap” (77h) command can
either enable or disable the “Wrap Around” feature for the following ECh 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.
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Publication Release Date: September 20, 2016
Revision B