W25X10A, W25X20A, W25X40A, W25X80A
10.2 INSTRUCTIONS
The instruction set of the W25X10A/20A/40A/80A consists of fifteen basic instructions that are fully
controlled through the SPI bus (see Instruction Set table). Instructions are initiated with the falling
edge of Chip Select (/CS). The first byte of data clocked into the DIO input provides the instruction
code. Data on the DIO input is sampled on the rising edge of clock with most significant bit (MSB) first.
Instructions vary in length from a single byte to several bytes and may be followed by address bytes,
data bytes, dummy bytes (don’t care), and in some cases, a combination. Instructions are completed
with the rising edge of edge /CS. Clock relative timing diagrams for each instruction are included in
figures 4 through 19. All read instructions can be completed after any clocked bit. However, all
instructions that Write, Program or Erase must complete on a byte boundary (CS driven high after a
full 8-bits have been clocked) otherwise the instruction will be terminated. This feature further protects
the device from inadvertent writes. Additionally, while the memory is being programmed or erased, or
when the Status Register is being written, all instructions except for Read Status Register will be
ignored until the program or erase cycle has completed.
10.2.1 Manufacturer and Device Identification
MANUFACTURER ID
(M7-M0)
Winbond Serial Flash
EFh
(ID15-ID0)
9Fh
Device ID
Instruction
W25X10A
W25X20A
W25X40A
W25X80A
(ID7-ID0)
ABh, 90h
10h
3011h
3012h
3013h
3014h
11h
12h
13h
- 14 -
WINBOND [ WINBOND ]
