Instructions
M25P64
6
Instructions
All instructions, addresses and data are shifted in and out of the device, most significant bit
first.
Serial Data Input (D) is sampled on the first rising edge of Serial Clock (C) after Chip Select
(S) is driven Low. Then, the one-byte instruction code must be shifted in to the device, most
significant bit first, on Serial Data Input (D), each bit being latched on the rising edges of
Serial Clock (C).
The instruction set is listed in Table 4.
Every instruction sequence starts with a one-byte instruction code. Depending on the
instruction, this might be followed by address bytes, or by data bytes, or by both or none.
In the case of a Read Data Bytes (READ), Read Data Bytes at Higher Speed (Fast_Read),
Read Status Register (RDSR), Read Identification (RDID) or Read Electronic Signature
(RES) instruction, the shifted-in instruction sequence is followed by a data-out sequence.
Chip Select (S) can be driven High after any bit of the data-out sequence is being shifted
out.
In the case of a Page Program (PP), Sector Erase (SE), Bulk Erase (BE), Write Status
Register (WRSR), Write Enable (WREN) or Write Disable (WRDI), Chip Select (S) must be
driven High exactly at a byte boundary, otherwise the instruction is rejected, and is not
executed. That is, Chip Select (S) must driven High when the number of clock pulses after
Chip Select (S) being driven Low is an exact multiple of eight.
All attempts to access the memory array during a Write Status Register cycle, Program
cycle or Erase cycle are ignored, and the internal Write Status Register cycle, Program
cycle or Erase cycle continues unaffected.
Table 4.
Instruction set
Description
One-byte instruction Address
Dummy
bytes
Data
bytes
Instruction
code
bytes
WREN
WRDI
RDID
Write Enable
0000 0110
0000 0100
1001 1111
0000 0101
0000 0001
0000 0011
06h
04h
9Fh
05h
01h
03h
0
0
0
0
0
3
0
0
0
0
0
0
0
Write Disable
0
Read Identification
Read Status Register
Write Status Register
Read Data Bytes
1 to 3
1 to ∞
1
RDSR
WRSR
READ
1 to ∞
Read Data Bytes at
Higher Speed
FAST_READ
PP
0000 1011
0000 0010
0Bh
02h
3
3
1
0
1 to ∞
1 to
256
Page Program
SE
BE
Sector Erase
1101 1000
1100 0111
1010 1011
D8h
C7h
ABh
3
0
0
0
0
3
0
0
Bulk Erase
RES
Read Electronic Signature
1 to ∞
22/50
NUMONYX [ NUMONYX B.V ]
