ESMT
F25L08QA (2S)
Mode Bit Reset
Mode bits [M7 –M0] are issued to further reduce instruction
overhead for Fast Read Dual/Quad I/O operation. If [M7 –M0] =
“AxH”, the next Fast Read Dual/Quad I/O instruction doesn’t
need the command code.
However, the device doesn’t have a hardware reset pin, so if
[M7 –M0] = “AxH”, the device will not recognize any standard SPI
instruction. After a system reset, it is recommended to issue a
Mode Bit Reset instruction first to release the status of [M7 –M0] =
“AxH” and allow the device to recognize standard SPI instruction.
See Figure 12 for the Mode Bit Reset instruction.
If the system controller is reset during operation, it will send a
standard instruction (such as Read ID) to the Flash memory.
Mode bit Reset for Dual I/O
Mode bit Reset for Quad I/O
CE
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15
MODE3
SCK MODE0
SIO0
SIO1
FF
FF
SIO2
SIO3
Note: To reset mode bits during Quad I/O operation, only eight clocks are needed. The command code is “FFH”.
To reset mode bits during Dual I/O operation, sixteen clocks are needed to shift in command code “FFFFH”.
Figure 12: Mode Bit Reset Instruction
Elite Semiconductor Memory Technology Inc.
Publication Date: Nov. 2013
Revision: 1.2 21/43
ESMT [ ELITE SEMICONDUCTOR MEMORY TECHNOLOGY INC. ]
