How to configure GPIO as data and address bus

[vn2000]

My nRF52840 DK needs to interface with a convential device using the data bus and address bus.
The following diagram (P.27) from the nRF52840 PDK user guide.shows the data/address bus assignments.

How do I configure the GPIO assigned to the data lines to be bidirectional?

[Vidar Berg]

Hi,

What kind of bus does the device support, SPI, UART, i2c, or something else? The GPIOs are not bidirectional. 

Please also note that the nRF52840 PDK (preview-DK) is no longer supported. This board has an early engineering version of the nRF52840 chip which has several hardware limitations and erratas that may prevent your code from running properly.

Best regards,

Vidar

[vn2000]

The device is an DAC with parallel 12-bit data bus and some address lines. Not I2C, not SPI, not UART. It is just a conventional device with data and address lines as used in the early days of the microprocessor.. It also needs a RD and WR signal, but I can work it out.

So the question is can we use the nRF52840 DK to interface with a parallel data device.Here is another device using parallel data bus: S29GL512 Flash Memory

[Vidar Berg]

There is no hardware support for parallel interfaces in HW, but I assume bit banging should be possible. Although it won't be efficient. You will need to configure the GPIOs as outputs when sending data and reconfigure them as inputs when receiving data.

[vn2000]

Ok I will go with bit banging. Not very efficient but that's the only way to go.