RoyalTek
Confidential
14
REB-1722 Operational Manual
Reset_N
This pin provides an active-low reset input to the board. It causes the board to reset and
start searching for satellites. If not utilized, it may be left open.
TIMEMARK
This pin provides one pulse-per-second output from the board, which is synchronized to
GPS time.
V_RTC_3V3 (Backup battery)
This is the battery backup input that powers the SRAM and RTC when main power is
removed. Typical current draw is 10uA.
The supply voltage should be between 1.4V and 3.6V.
GPIO Functions (SCL2, SDA2, CFG_COM1, AADET0_N, EXTINT0)
Several I/Os are connected to the digital interface connector for custom applications.
AADET0_N
AADET0_N is an input pin and it is used to report whether an external circuit has
detected an external antenna or not. Low means antenna has been detected. High means
no external antenna has been detected.
