T25S16AFEPR datasheet(64/74 Pages) HMSEMI

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the number of dummy clocks for “Fast Read (0Bh)”, “Fast Read Quad I/O (EBh)” & “Burst Read with Wrap

(0Ch)” instructions, and to configure the number of bytes of “Wrap Length” for the “Burst Read with Wrap

(0Ch)” instruction.

In Standard SPI mode, the “Set Read Parameters (C0h)” instruction is not accepted. The dummy clocks

for various Fast Read instructions in Standard/Dual/Quad SPI mode are independently controlled by SR3[3:0],

see details in Table 6.5. The “Wrap Length” is set by W6-5 bit in the “Set Burst with Wrap (77h)” instruction.

This setting will remain unchanged when the device is switched between Standard SPI mode and QPI mode.

The default “Wrap Length” after a power up or a Reset instruction is 8 bytes, the default number of

dummy clocks is 2. The number of dummy clocks is only programmable for “Fast Read (0Bh)”, “Fast Read

Quad I/O (EBh)” & “Burst Read with Wrap (0Ch)” instructions in the QPI mode. Whenever the device is

switched from SPI mode to QPI mode, the number of dummy clocks should be set again, prior to any 0Bh,

EBh or 0Ch instructions.

P5-P4

DUMMY

CLOCKS

MAXIMUM

READ FREQ.

MAXIMUM READ

FREQ.(A[1:0]=0,0)

50MHz

80MHz

104MHz

P1-P0

WRAP

LENGTH

8-byte

16-byte

32-byte

64-byte

Figure 7.44 Set Read Parameters Instruction (QPI Mode only)

7.5.18 Burst Read with Wrap (0Ch)

The “Burst Read with Wrap (0Ch)” instruction provides an alternative way to perform the read operation

with “Wrap Around” in QPI mode. The instruction is similar to the “Fast Read (0Bh)” instruction in QPI mode,

except the addressing of the read operation will “Wrap Around” to the beginning boundary of the “Wrap

Length” once the ending boundary is reached. The “Wrap Length” and the number of dummy clocks can be

configured by the “Set Read Parameters(C0h)” instruction.

Figure 7.45 Burst Read with Wrap Instruction (QPI Mode only)

HM25Q128A

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