Eurotech Appliances PXA270 On-BoardGPIO expanders pin assignments, Dir, Dir, GPIO, Key:, state, Active, Active, Power-up, Function, Signal name, See section…, - Open Drain, Pin direction

ZEUS Technical Manual Detailed hardware description

On-Board GPIO expanders pin assignments

Two GPIO expanders (MAX7313) are used to provide additional GPIOs for use with different on-board peripherals. The GPIO expanders are connected to the I2C bus of PXA270 and are accessible through I2C bus addresses 0x21 and 0x22.

The following tables summarize the use of the 17 GPIO pins of MAX7313 on ZEUS board, and indicate their direction and active level.

Expander 1 - I2C Address 0x21
									Power-up
GPIO			Signal name	Dir	Active		Function		state	See section…
	0		U3_RS232EN	Output	High		UART3 RS232 enable		PU
1			U3_RS422EN	Output	High		UART3 RS422 enable		PU	COM3 –
										RS232/RS485/RS422
2			U3_TERM#	Output	Low		UART3 termination		PU	interface, page 54
							enable
3			USER_LED1# Output		Low		User LED 1		PU
4			USER_LED2# Output		Low		User LED 2		PU	User LEDs, page 96
5			USER_LED3# Output		Low		User LED 3		PU
6			USER_LINK3	Input	NA		User jumper 3		Jumper	JP1 – User jumpers, page 93
7			NOT USED						PU
8			GSM_ON	Output	See note		Modem enable		OD
					1 below
9			GSM_STS	Input	High		Modem ON/OFF status		Low
10			GPS_ON	Output	High		GPS module enable		PU	Wireless modem and GPS
										receiver, page 35
11			GPS_PSUON Input		NA		Not Used		PU
12			GPS_BOOT	Input	NA		Not Used		OD
13			GPS_PPS	Input	NA		GPS Pulse Per Second		-
14			USER_LINK4	Input	NA		User jumper 4		Jumper	JP1 – User jumpers,
										page 93
15			U4_RS485EN	Output	High		UART4 RS485 enable		PU	COM4 – RS422/485
16			U4_TERM#	Output	Low		UART4 termination		PU	interface, page 55
							enable
Key:
Dir		-	Pin direction			Active		- Function active level or edge
PU		-	On-board 10K pull-up			OD		- Open Drain

Note 1: Please see the datasheet of the particular module used.

© 2007 Eurotech Ltd Issue D 29