5340 spim + display question

[hbenchoi]

Hi.

I use 5340 + spim 32M (nrfx driver) + ncs 2.0.2 + LVGL library. (display driver ic is RM69090)

I try to communicate display with spim and success work. but refresh is slow to display animation.

so I search and found this section in display driver. 

I used spi4 1wire. i try to use 2wire. i guess that data can send more fast than 1wire.

however in 2wire dcx also use data line. now i just use  nrfx_spim_xfer_dcx function and I couldn't  find any function that dcx send data.

1. Is any function to support 2wire? or I need to write driver myself?

2. is any other way? (use qspi?)

thank you.

Best Regards

Ben

[Joost Voorhaar]

Check the nRF5340 datasheet for the SPIM peripheral. As far as I know, you cannot use DCX to actually send data, all data from SPIM4 is sent through MOSI only. 

The driver in nrfx can be used to toggle dcx to distinguish between command and data, but it will just stay low or high during the transmission of a byte. In order to use it in nRF Connect SDK, define the following in your project configuration:

# Display
CONFIG_NRFX_SPIM4=y
CONFIG_SPI_NRFX=y
CONFIG_SPI=y
CONFIG_SPI_4_NRF_RX_DELAY=0
 

Note: the last line will enable DCX control (SPIM4 only). 

There's a small example available in this thread:  Where do I configure nrfx internae? 

[hbenchoi]

thank reply.

I already used spm4 32M but need more faster. or check more optimize code or anything else.