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5. Interface Description

5.

Interface Description

5.1. Address Space

The SPI/QPI PSRAM device is byte-addressable. The address of the 64 Mbit device is A[22:0].

5.2. Page Size

The page size is 1K (CA[9:0]). The default setting is a linear burst that crosses page boundaries in

a continuous manner. Note, however, that the maximum input clock frequency for burst operations

which cross page boundaries is 84 MHz. Optionally, the device can also be set to the 32-byte wrap

(CA[4:0]) mode, using the Wrap Boundary Toggle command, but the device cannot cross page

boundaries in this case.

5.3. Power-on Status

The device powers up in SPI Mode. It is required to have CE# high before beginning any opera-

tions.

5.4. Truth Table

The device recognizes the following commands specified by the various input methods.

Command

Code

SPI Mode (QE=0)

QPI Mode (QE=1)

Cmd

Addr

Wait

Cycle DIO

MAX

Freq.

Cmd

Addr

Wait

Cycle

DIO MAX Freq.

Read

'h03

0

S

33

N/A

Fast Read

'h0B

S

S

8

S

133/144 N/A

Fast Read

Quad

'hEB

S

Q

6

1

133/144 Q

Q

6

Q

Write

'h02

S

S

0

S

133/144 Q

Q

0

Q

Quad Write

'h38

S

Q

0

Q

133/144 Same as 'h02

Enter Quad

Mode

'h35

S

-

-

-

133/144 N/A

Exit Quad

Mode

'hF5

N/A

Q

-

-

-

133/144

Reset

Enable

'h66

S

-

-

-

133/144 Q

-

-

-

133/144

Reset

'h99

S

-

-

-

133/144 Q

-

-

-

133/144

Espressif Systems

" /"

2018.06

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