15

4890AS–GPS–09/05

ATR0621 [Preliminary]

Table 3-15.

Recommended Pin Connection

Pin Name

Recommended External Circuit

P0/NANTSHORT

Internal pull-down resistor; can be left open.

P1/GPSMODE0

Pull-up resistor to VDD18 or pull-down resistor to GND if used as input by user application; connect to

GND or VDD18 if unused or used as GPSMODE pin only. See GPSMODE definitions in “Setting

GPSMODE0 to GPSMODE12” on page 10. Can be left open if configured as output by user application. If

this pin is left open, the GPSMODE pin configuration feature must be completely disabled by user

application.

P2/BOOT_MODE

Internal pull-down resistor, leave open.

P3/NCS1

Output in default ROM firmware: leave open; only needs pull-up resistor to VDD18 or pull-down resistor

to GND if used as GPIO input by user application and not always driven from external sources.

P4/NCS0

Output in default ROM firmware: leave open; only needs pull-up resistor to VDD18 or pull-down resistor

to GND if used as GPIO input by user application and not always driven from external sources.

P5/NWE/NWR0

Output in default ROM firmware: leave open; only needs pull-up resistor to VDD18 or pull-down resistor

to GND if used as GPIO input by user application and not always driven from external sources.

P6/NOE/NRD

Output in default ROM firmware: leave open; only needs pull-up resistor to VDD18 or pull-down resistor

to GND if used as GPIO input by user application and not always driven from external sources.

P7/NUB/NWR1

Output in default ROM firmware: leave open; only needs pull-up resistor to VDD18 or pull-down resistor

to GND if used as GPIO input by user application and not always driven from external sources.

P8/STATUSLED

Output in default ROM firmware: leave open; only needs pull-up resistor to VDD18 or pull-down resistor

to GND if used as GPIO input by user application and not always driven from external sources.

P9/EXTINT0

Pull-up resistor to VDD18 or pull-down resistor to GND or connect to GND or VDD18 if unused. Never

leave open.

P10/EM_A0/NLB

Output in default ROM firmware: leave open; only needs pull-up resistor to VDD18 or pull-down resistor

to GND if used as GPIO input by user application and not always driven from external sources.

P11/EM_A21

Pull-up resistor to VDD18 or pull-down resistor to GND (this pin is used as address line EM_A21 by

standard firmware, do not connect to GND or VDD18 directly). Never leave open.

P12/NCS2/GPSMODE2

Pull-up resistor to VDD18 or pull-down resistor to GND if used as input by user application, or connect to

GND or VDD18 if unused or used as GPSMODE pin only. See GPSMODE definitions in “Setting

GPSMODE0 to GPSMODE12” on page 10. Can be left open if not used as GPSMODE pin and

configured as output by user application.

P13/EXTINT1/GPSMODE3/

NCS3

Pull-up resistor to VDD18 or pull-down resistor to GND if used as input by user application, or connect to

GND or VDD18 if unused or used as GPSMODE pin only. See GPSMODE definitions in section “Setting

GPSMODE0 to GPSMODE12” on page 10. Never leave open.

P14/SCK0/GPSMODE4

Pull-up resistor to VDD18 or pull-down resistor to GND if used as input by user application; connect to

GND or VDD18 if unused or used as GPSMODE pin only. See GPSMODE definitions in “Setting

GPSMODE0 to GPSMODE12” on page 10. Can be left open if not used as GPSMODE pin and

configured as output by user application.

P15/ANTON

Internal pull-down resistor; can be left open.

P16/NWD_OVF

Output in default ROM firmware: leave open; only needs pull-up resistor to VDD18 or pull-down resistor

to GND if used as GPIO input by user application and not always driven from external sources.

P17/SCK1/GPSMODE5

Pull-up resistor to VDD18 or pull-down resistor to GND if used as input by user application; connect to

GND or VDD18 if unused or used as GPSMODE pin only. See GPSMODE definitions in “Setting

GPSMODE0 to GPSMODE12” on page 10. Can be left open if not used as GPSMODE pin and

configured as output by user application.

P18/TXD1

Output in default ROM firmware: leave open; only needs pull-up resistor to VDD18 or pull-down resistor

to GND if used as GPIO input by user application and not always driven from external sources.

Note:

“Never leave open” means: This pin needs a defined level, even if VDD18 is not supplied and system is in backup mode.