M25PE10, M25PE20
Read Data Bytes at Higher Speed
(FAST_READ)
next higher address after each Byte of data is shift-
ed out. The whole memory can, therefore, be read
with a single Read Data Bytes at Higher Speed
(FAST_READ) instruction. When the highest ad-
dress is reached, the address counter rolls over to
000000h, allowing the read sequence to be contin-
ued indefinitely.
The Read Data Bytes at Higher Speed
(FAST_READ) instruction is terminated by driving
Chip Select (S) High. Chip Select (S) can be driv-
en High at any time during data output. Any Read
Data Bytes at Higher Speed (FAST_READ) in-
struction, while an Erase, Program or Write cycle
is in progress, is rejected without having any ef-
fects on the cycle that is in progress.
The device is first selected by driving Chip Select
(S) Low. The instruction code for the Read Data
Bytes at Higher Speed (FAST_READ) instruction
is followed by a 3-Byte address (A23-A0) and a
dummy Byte, each bit being latched-in during the
rising edge of Serial Clock (C). Then the memory
contents, at that address, is shifted out on Serial
Data Output (Q), each bit being shifted out, at a
maximum frequency f , during the falling edge of
C
Serial Clock (C).
The instruction sequence is shown in Figure 13.
The first Byte addressed can be at any location.
The address is automatically incremented to the
Figure 13. Read Data Bytes at Higher Speed (FAST_READ) Instruction Sequence
and Data-Out Sequence
S
0
1
2
3
4
5
6
7
8
9
10
28 29 30 31
C
Instruction
24 BIT ADDRESS
23 22 21
3
2
1
0
D
Q
High Impedance
S
C
47
32 33 34 35 36 37 38 39 40 41 42 43 44 45 46
Dummy Byte
7
6
5
4
3
2
0
1
D
Q
DATA OUT 2
DATA OUT 1
7
6
5
4
3
2
1
0
7
7
6
5
4
3
2
0
1
MSB
MSB
MSB
AI04006
Note: Address bits A23 to A18 are Don’t Care in the M25PE20. Address bits A23 to A17 are Don’t Care in the M25PE10.
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STMICROELECTRONICS [ ST ]
