Data Sheet

NEO-M8P - Data Sheet
UBX-15016656 - R06 Early Production Information Configuration management
Page 18 of 30
3 Configuration management
Configuration settings can be modified with UBX configuration messages. The modified settings remain effective
until power-down or reset. Settings can also be saved in battery-backed RAM, Flash or both using the UBX-CFG-
CFG message. If settings have been stored in battery-backed RAM then the modified configuration will be
retained as long as the backup battery supply at V_BCKP is not interrupted. Settings stored in Flash memory will
remain effective even after power-down and do not require a backup battery supply.
3.1 Interface selection (D_SEL)
At startup, Pin 2 (D_SEL) determines which data interfaces are used for communication. If D_SEL is set high or
left open, UART and DDC become available. If D_SEL is set low, i.e. connected to ground, the NEO-M8P module
can communicate to a host via SPI.
PIN #
D_SEL=”1”
(left open)
D_SEL =”0”
(connected to GND)
20 UART TX SPI MISO
21 UART RX SPI MOSI
19 DDC SCL SPI CLK
18 DDC SDA SPI CS_N
Table 8: Data interface selection by D_SEL