IS66/67WVR4M8ALL/BLL

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

19

Rev. A2

07/08/2024

5.8 RESET OPERATION

Software RESET

The software reset operation is used as a system reset that puts the device in SPI standby mode, which is

also the default mode after power up. This operation consists of two commands: RESET Enable (0x66h) and

RESET (RST, 0x99).

The reset operations requires the RESET ENABLE command to be followed by the RESET command. Any

other command other than the RESET command after the RESET ENABLE command will disable the

RESET ENABLE procedure.

Figure 5.13 SPI RESET

CE#

CLK

SI

0

1

2

3

4

5

6

7

8

9

10 11

12 13 14 15 16

0

1

1

0

0

1

1

0

1

0

0

1

1

0

0

1

Reset Enabe CMD (66h)

Reset CMD (99h)

Figure 5.14 QPI RESET

CE#

CLK

Cmd

RSTEN

SIO[3:0]

0

1

6

6

2

3

4

9

9

Cmd

RST