W25M02GV
8.2.19 Fast Read Dual Output (3Bh)
The Fast Read Dual Output (3Bh) instruction is similar to the standard Fast Read (0Bh) instruction except
that data is output on two pins; IO0 and IO1. This allows data to be transferred at twice the rate of standard
SPI devices.
The Fast Read Dual Output instruction sequence is shown in Figure 22a & 22b. When BUF=1, the device
is in the Buffer Read Mode. The data output sequence will start from the Data Buffer location specified by
the 16-bit Column Address and continue to the end of the Data Buffer. Once the last byte of data is output,
the output pin will become Hi-Z state. When BUF=0, the device is in the Continuous Read Mode, the data
output sequence will start from the first byte of the Data Buffer and increment to the next higher address.
When the end of the Data Buffer is reached, the data of the first byte of next memory page will be
following and continues through the entire memory array. This allows using a single Read instruction to
read out the entire memory array and is also compatible to Winbond’s SpiFlash NOR flash memory
command sequence.
Figure 22a. Fast Read Dual Output Instruction (Buffer Read Mode, BUF=1)
Figure 22b. Fast Read Dual Output Instruction (Continuous Read Mode, BUF=0)
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