External memory of nRF9160 DK

The nRF9160 DK has a 64 Mb external flash memory. The memory is a multi-I/O memory supporting both SPIs.

The memory is connected to the chip using the following General-Purpose Input/Output (GPIO)s:

Table 1. Flash memory GPIO usage, solder bridges and testpoints
GPIO	Flash memory pin	Solder bridge for default use	Testpoint
P0.25	CS	SB23	TP57
P0.13	SCLK	N/A	N/A
P0.11	SIO_0/SI	N/A	N/A
P0.12	SIO_1/SO	N/A	N/A
N/A	SIO_2/WP	N/A	TP55
N/A	SIO_3/HOLD	N/A	TP56

The flash memory CS pin is by default connected to P0.25, this pin is also used for trace. To be able to use the external memory together with trace, Solder bridge SB23 can be cut and a wire can be strapped from test point TP57 to a GPIO of choice. The WP and HOLD pins of the external memory are available only on test points TP55 and TP56, and to use these, wires can be strapped form the test points to the GPIOs of choice.

Figure 1. Flash memory