EN25F40A
Full Quad SPI Modes (QPI)
The EN25F40A also supports Full Quad SPI Mode (QPI) function while using the Enable Quad
Peripheral Interface mode (EQPI) (38h). When using Quad SPI instruction the DI and DO pins become
bidirectional I/O pins; DQ0 and DQ1, and the WP# and HOLD# pins become DQ2 and DQ3 respectively.
Figure 5. Full Quad SPI Modes
Page Programming
To program one data byte, two instructions are required: Write Enable (WREN), which is one byte, and
a Page Program (PP) or Quad Input Page Program (QPP) sequence, which consists of four bytes plus
data. This is followed by the internal Program cycle (of duration tPP).
To spread this overhead, the Page Program (PP) or Quad Input Page Program (QPP) instruction allows
up to 256 bytes to be programmed at a time (changing bits from 1 to 0) provided that they lie in
consecutive addresses on the same page of memory.
Sector Erase, Half Block Erase, Block Erase and Chip Erase
The Page Program (PP) or Quad Input Page Program (QPP) instruction allows bits to be reset from 1 to
0. Before this can be applied, the bytes of memory need to have been erased to all 1s (FFh). This can
be achieved a sector at a time, using the Sector Erase (SE) instruction, half a block at a time using the
Half Block Erase (HBE) instruction, a block at a time using the Block Erase (BE) instruction or
throughout the entire memory, using the Chip Erase (CE) instruction. This starts an internal Erase cycle
(of duration tSE, tHBE, tBE or tCE). The Erase instruction must be preceded by a Write Enable (WREN)
instruction.
Polling During a Write, Program or Erase Cycle
A further improvement in the time to Write Status Register (WRSR), Program (PP, QPP) or Erase (SE,
HBE, BE or CE) can be achieved by not waiting for the worst case delay (tW, tPP, tSE, tHBE, tBE or tCE). The
Write In Progress (WIP) bit is provided in the Status Register so that the application program can
monitor its value, polling it to establish when the previous Write cycle, Program cycle or Erase cycle is
complete.
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
Elite Semiconductor Memory Technology Inc.
8
Rev. D, Issue Date: 2017/02/13