M25PX32 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'M25PX32' PDF : 63 Pages View PDF
Instructions
M25PX32
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 fC,
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.
When the highest address is reached, the address counter rolls over to 00 0000h, so that
the read sequence can be continued indefinitely.
Figure 15. Dual Output Fast Read instruction sequence
S
Mode 3
C Mode 2
DQ0
0 1 2 3 4 5 6 7 8 9 10 28 29 30 31
Instruction
24-bit address
23 22 21 3 2 1 0
DQ1
High Impedance
S
32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
C
Dummy byte
DQ0
DQ1
1. A23 to A22 are Don't care.
642064206420 6420
DATA OUT 1 DATA OUT 2 DATA OUT 3 DATA OUT n
753175317531
MSB
MSB
MSB
7531
MSB
MSB
ai13574
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