M25PX16
Instructions
Figure 14. 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
DQ0
DQ1
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
DQ0
DQ1
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
AI13737
1. Address bits A23 to A22 are Don’t care.
6.8
Dual Output Fast Read (DOFR)
The Dual Output Fast Read (DOFR) instruction is very similar to the Read Data Bytes at
higher speed (FAST_READ) instruction, except that the data are shifted out on two pins (pin
DQ0 and pin DQ1) instead of only one. Outputting the data on two pins instead of one
doubles the data transfer bandwidth compared to the Read Data Bytes at higher speed
(FAST_READ) instruction.
The device is first selected by driving Chip Select (S) Low. The instruction code for the Dual
Output 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, are shifted out on DQ0 and DQ1 at a maximum frequency f ,
C
during the falling edge of Serial Clock (C).
The instruction sequence is shown in Figure 15.
The first byte addressed can be at any location. The address is automatically incremented
to the next higher address after each byte of data is shifted out on DQ0 and DQ1. The whole
memory can, therefore, be read with a single Dual Output Fast Read (DOFR) instruction.
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MICRON [ MICRON TECHNOLOGY ]
