IS66/67WVR4M8ALL/BLL

Integrated Silicon Solution, Inc.- www.issi.com

16

Rev. A2

07/08/2024

5.4 QPI FAST READ OPERATION

For all reads in QPI mode, data will be available for tACLK after the falling edge of clock. QPI reads can be done

in two ways:

03h: Quad CMD, Quad IO, fast frequency (up to 84MHz, 4 Wait Cycles)

0Bh: Quad CMD, Quad IO, fast frequency (up to 84MHz, 4 Wait Cycles)

EBh: Quad CMD, Quad IO, fast frequency (up to 104MHz, 6-Wait Cycles)

Figure 5.7 QPI Fast Read, 03h/0Bh (Max Frequency: 84MHz)

CE#

CLK

Cmd

Read

SIO[3:0]

0

1

0

B

2

3

4

5

6

7

8

9

10

11

23:20

15:12

7:4

3:0

11:8

19:16

24 Bits Address

12

Data Out 1

13

14

7:4

3:0

7:4

3:0

Data Out 2

Wait Cycles

(4 Clocks)

High-Z

tACLK

Note:

1. Data out goes to High-Z after CE# transitions to HIGH (tHZ).

Figure 5.8 QPI Fast Read, EBh (Max Frequency: 104MHz)

CE#

CLK

Cmd

Read

SIO[3:0]

0

1

E

B

2

3

4

5

6

7

8

9

10

13

23:20

15:12

7:4

3:0

11:8

19:16

24 Bits Address

14

Data Out 1

15

16

7:4

3:0

7:4

3:0

Data Out 2

Wait Cycles

(6 Clocks)

High-Z

tACLK

11

12

Note:

1. Data out goes to High-Z after CE# transitions to HIGH (tHZ).