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