nRF7002 QSPI commands

nRF7002 supports several Quad Serial Peripheral Interface (QSPI) commands.

Table 1. QSPI commands
Command (byte)	RDSR (read status register 0)	RDSR1 (read status register 1)	RDSR2 (read status register 2)	WRSR2 (write status register 2)	CIPHER INIT (Initialize cipher)	FAST READ (fast read data)	READ4 (4 x I/O read command)	PP (Page program)	PP4 (Quad page program)
1st byte	0x05	0x1F	0x2F	0x3F	0x4F	0x0B	0xEB	0x02	0x38
2nd byte					NONCE1	AD1	ADD (4) and Dummy (4)	AD1	ADD (4)
3rd byte					NONCE2	AD2	Dummy (4)	AD2
4th byte					NONCE3	AD3		AD3
5th byte					NONCE4	Dummy
Action	To read out the values of status register 0	To read out the values of status register 1	To read out the values of status register 2	To write in the values of status register 2	To enable the steam cipher and initialize the NONCE register	n bytes read out until SS goes high	n bytes read out by 4 x I/O until SS goes high	to program the selected page	Quad input to program the selected page

For RDSR, RDSR1, RDSR2, FAST_READ, and READ4, the shifted-in instruction sequence is followed by a data-out sequence. After any bit of data being shifted out, the SS can be high.

For CIPHER_INIT, PP, and PP4, the SS must go high exactly at the 4th byte (32 bits) boundary or the value will not be stored.

For WRSR2, the SS must go high exactly at the 1st byte (8 bits) boundary or the value will not be stored.

The following figure shows the timing diagram for the RDSR command. The other commands that access status registers have the same format but with a different 1st byte.

Figure 1. RDSR (Read status register 0)

The following figure shows the timing diagram for the cipher initialization command.

Figure 2. CIPHER INIT (Initialize cipher)

The following figures show the timing diagram for the data read and program commands.

Figure 3. FASTREAD (Read bytes at higher speed)

Figure 4. READ4IO (Quad-read input/output)

Figure 5. PP (Page program)

Figure 6. PP4IO (Quad-page program input/output)