User Manual

Table Of Contents
XT55/56 Hardware Interface Description
Confidential / Preliminary
s
XT55/56_hd_v02.96 Page 95 of 125 18.08.2005
Function Signal name IO Signal form and level Comments
Digital Input /
Output
GPS_GPIO14 I/O CMOS 3.3V DC level See Chapter 4.5
Digital Input /
Output
GPS_GPIO15 I/O CMOS 3.3V DC level See Chapter 4.5
GPS Reset GPS_M-RST I CMOS 3.3V DC level Active low reset input
Serial1 Rx GPS_SDI1 I CMOS 3.3V DC level See Chapter 4.6
Serial1 Tx GPS_SDO1 O CMOS 3.3V DC level See Chapter 4.6
Digital Input GPS_BOOTSEL I CMOS 3.3V DC level For re-programming the
Flash must be set to High
Digital Input GPS_RFPC1 I CMOS 3.3V DC level
Connect to GPS_GPIO4
including the pull-up
resistors as shown in Figure
58
Digital Input GPS_RFPC0 I CMOS 3.3V DC level
Connect to GPS_GPIO8
including the pull-up
resistors as shown in Figure
58
Serial2 Rx GPS_SDI2 I CMOS 3.3V DC level See Chapter 4.6
Serial2 Tx GPS_SDO2 0 CMOS 3.3V DC level See Chapter 4.6
CMOS 3.3V level:
Input High = 2.0 – 3.3 V DC; I_leakage = 2µA
Input Low = 0 – 0.8 V DC, I_leakage = 2µA
Output High = min. 2.4 V DC, I
oh
= 2mA
Output Low = max 0.4 V DC, I
oh
= 2mA