About SPI opcode 0x03

[wiz_yoo]

Hello. 

I am yoo at korea.

We will connect OLED with QSPI and Driver IC supports SLOWREAD.

- 8bit (Opcode: 0x03) + 24bit  (Addr) + 8bit (Read value: Mandatory) + 8bit (Read value: Optional) ... + 8bit (Read value: Optional) 

According to "6.19.8 instruction set" of nRF52840_PS_v1.5.pdf, there is no opcode 0x03 (SLOWREAD).

My question is as follows.

1. Is it possible add opcode 0x03?

2. Could I use "6.19.6 Sending custom instructions" for opcode 0x03.

Thank you.

Best Regrads.

[haakonsh]

Hey Yoo,

It depends on the device it is interfacing with, can you share a part number?

BR,

Håkon Holdhus

[wiz_yoo]

Dear haakonsh.

I am sorry for late reply.

Currently, I don't know the part number and only know what to implement.

The communication specifications currently provided are as follows.
- Write/read operation should be performed with IO0.

Is it supported by nRF52840 QSPI?

BR,

Thank you.

[haakonsh]

There is one problem with custom instructions, the QSPI peripheral will operate as a regular SPI master, with one MISO and one MOSI. See Figure 3. Sending custom instruction in the Instruction set chapter.

[wiz_yoo]

Hi, Håkon Holdhus

Thank you for answer.

I know that this is not a regular SPI operation.

If not supported, we would like to make custom QSPI driver.

If you have any reference materials, please.

Best regrads,

Yoo

[haakonsh]

Hey Yoo, 

I'm afraid the QSPI peripheral only supports the specified Instruction set. The QSPI is tailored for flash devices and is not a generic QSPI peripheral. I will ask my colleagues if we have any work-around for this issue. If we could get any information on the display and it's spec we could tell you definitely whether we can support it or not. 

BR,
Håkon Holdhus.

[wiz_yoo]

Hi, Håkon Holdhus

We will change interface QSPI to SPI.

So, there is no need to review the above item.

Thank you for support.

Best regrads,

Yoo