	Fox G20 SERIAL PORT NOTES
	=-=-=-=-=-=-=-=-=-=-=-=-=


Fox G20 serial ports
====================
All serial pins are at 3.3 volt TTL levels unless otherwise noted.
The "LX_name" is what the corresponding pins on the J6 and J7
connectors are on the FoxLX.

AT91_name   linux_name   LX_name       notes
-------------------------------------------------
 DTXD       /dev/ttyS0   TXD0(ttyS0)   2 wire  
 TXD0       /dev/ttyS1   TXD2(ttyS2)   8 wire (RTS+CTS+DCD+DTR+DSR+RI)
 TXD1       /dev/ttyS2   TXD3(ttyS3)   4 wire (RTS+CTS)
 TXD2       /dev/ttyS3                 2 wire (hidden RTS+CTS)
 TXD3       /dev/ttyS4                 4 wire (1.8 volt RTS+CTS)
 TXD4       /dev/ttyS5                 2 wire
 TXD5       /dev/ttyS6                 2 wire

For the GPIO lines these serial port use see the foxg20_gpio.txt
document.

Serial ports are configured by the kernel at boot time. If more
generic GPIO lines and less serial ports are needed then changes
could be made so the higher numbered serial ports were not
configured. User space programs (e.g. using mem2io) could
reconfigure GPIO lines after boot up.

On the Dasiy-1 adapter the ttyS4 RTS and CTS are level translated to
3.3 volt levels before they are brought out on the D6 connector. Thus
at the D6 connector TXD, RXD, RTS and CTS all have 3.3 volt levels.


D. Gilbert
20121101
