Motorola F3030A, Руководство разработчика

Страница: 25 / 72

98-08901C67-O 19
Developer Board and Interfaces Description
The USB jumper (P300) located next to the USB connector selects between the Developer Board USB interface and the UUT
USB interface. By changing the jumper position, the USB_VBUS signal is diverted to the selected driver (in the g20 or on the
Developer Board) and operates it.
3.4.2.3 SPI
The 9-pin D-type RS232-2 serial port (J500) is connected to the g20 internal SPI bus. This interface is used to debug applica-
tions. On the Developer Board, the g20 SPI interface is converted to standard RS232 signals for PC communications. The
conversion process uses the RS232 interface as a second slave on the internal g20 SPI bus, and communicates with it as such.
SPI read and write operations are performed normally, using the CS and IRQ signals provided by the conversion circuit. The
IRQ signal is connected to a g20 IRQ pin.
Table 11. USB Jumper (P300)
P300
Jumper
Position
Selected Mode USB Source
1 2 3
• •
g20 g20 driver
• •
EVB (Developer Board) EVB driver
USB disconnected
Note
The RS232-2 connector pin names are DTE-oriented.
Table 12. RS232-2 Connector Pinout (J500)
Pin # Description DTE I/O
1 Unused
2 RXD In
3 TXD Out
4 Unused
5 Ground
6 Unused
7 RTS Out
8 CTS In
9 Unused