External Memory SPI connection

[amarin]

Hi, 

I am currently working on programming a bootloader on to my nrf52840 DK. The bootloader will be able to do DFUs via SPI. I am using SDK 15.2.0. I also want to be able to write the update being received to an external EEPROM then transfer it over to internal memory (perform a dual bank update with eeprom). I am using an outside eeprom to use as external memory rather than the on board external memory. It communicates via 3 wire SPI, however, since I am already using an SPI connection, I am assuming that I could will be able to connect the EEPROM to the QSPI and disconnecting the external onboard memory. I currently have the EEPROM connected to my board as shown in the picture below. Vcc on the EEPROM is connected to VDD on the board.

 

I followed the instructions in this link to use the corresponding GPIOs. I then tested my connection using the nrfjprog --readqspi temp.hex . It was able to read the EEPROM and show it in temp.hex, but when I tried writing or erasing the memory, it would say the following:

 

I rerun nrfjprog --readqspi and it gives me the same values meaning that nrfjprog is not correctly erasing the EEPROM. I do not know if it is because I am using QSPI or if I am no connecting the external memory correctly. If it is because I am using QSPI, is there a way I can create another SPI connection on the board? And if so, how can I do that?

Any advice helps!!!

[Marjeris Romero]

Hi,

I followed the instructions in this link to use the corresponding GPIOs

Just to double check, have you soldered and cut the solder bridges needed to use these GPIOs for other purpose than using the onboard external in the DK?

To use the GPIOs for a purpose other than the onboard external memory and have them available on the P24 connector, six solder bridges (SB10–SB15) must be cut and six solder bridges (SB20–SB25) must be shorted. See the following figure for details.

Does your EEPROM support QSPI? Do you have a datasheet for this part available?

Best regards,

Marjeris

[amarin]

I have cut and soldered the corresponding bridges. I have two EEPROMs that I have available. The datasheet for one is in this link and the other is in this link. Both of them are able to communicate through SPI but none of them say anything about QSPI. If it is not working because the EEPROMs are not able to do QSPI, is it possible I could set up another SPI connection on the NRF52840 DK board? Is there an example in how to communicate with an external memory to communicate via SPI? 

[Marjeris Romero]

Hi,

amarin said:

Both of them are able to communicate through SPI but none of them say anything about QSPI

nrfjprog will not work unless the EEPROMs support QSPI and uses the same protocol as the external memory used in the nRF52840 DK.

amarin said:

is it possible I could set up another SPI connection on the NRF52840 DK board?

Yes, you have several instances of SPI to choose from, see the list and the supported configurations here: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fps_nrf52840%2Fspim.html&cp=4_0_0_5_24&anchor=topic__table.instances

Just check that you are not using other peripherals with the same peripheral ID as the SPIM instance you choose: https://infocenter.nordicsemi.com/topic/ps_nrf52840/peripheral_interface.html?cp=4_0_0_5_0_1#concept_shared_id

There is an SPI master example in the nRF5 SDK: https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.0.2/nrfx_spim_example.html

Best regards,

Marjeris

[amarin]

I decided to got with a different memory chip that does support QSPI, however, I am still running into the same problem where the chip is being read, but it cannot be erased or written to. I stored the read external memory using nrfjprog --readqspi temp.hex

temp.hex

I am currently running the qspi example found in the SDK and it shows the following output in the debug terminal:

<info> app: QSPI write and read example using 24bit addressing mode
<info> app: QSPI example started.
<info> app: Process of erasing first block start
<info> app: Process of writing data start
<info> app: Data read
<info> app: Compare...
<info> app: Data inconsistent

 

Do you have an idea as to why this is occurring? I still have it connected in the same way shown in my initial post.

[Marjeris Romero]

Hi,

I will do some investigations and come back to you on Monday.

Best regards,

Marjeris

[Marjeris Romero]

Sorry, I am still investigating this.