EN25Q128
Dual Input / Output FAST_READ (BBh)
The Dual I/O Fast Read (BBh) instruction allows for improved random access while maintaining two IO
pins, DQ0 and DQ1. It is similar to the Dual Output Fast Read (3Bh) instruction but with the capability to
input the Address bits (A23-0) two bits per clock. This reduced instruction overhead may allow for code
execution (XIP) directly from the Dual SPI in some applications.
The Dual I/O Fast Read instruction enable double throughput of Serial Flash in read mode. The
address is latched on rising edge of CLK, and data of every two bits (interleave 2 I/O pins) shift out on
the falling edge of CLK at a maximum frequency. The first address can be at any location. The address
is automatically increased to the next higher address after each byte data is shifted out, so the whole
memory can be read out at a single Dual I/O Fast Read instruction. The address counter rolls over to 0
when the highest address has been reached. Once writing Dual I/O Fast Read instruction, the following
address/dummy/data out will perform as 2-bit instead of previous 1-bit, as shown in Figure 14.
Figure 14. Dual Input / Output Fast Read Instruction Sequence Diagram
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc., www.eonssi.com
28
Rev. J, Issue Date: 2011/09/19
EON [ EON SILICON SOLUTION INC. ]
