TWR-SER2 User’s Manual
Page 8 of 17
3.5.2
Serial-to-USB
UART0 (RXD/TXD) is connected to a Freescale MC9S08JS16. The MC9S08JS16 provides a Serial-to-
USB conversion that will transmit/receive external data via its USB transceiver connected to an
USB mini-B connector. When this USB receptacle is connected to a host PC it will enumerate as a
USB CDC. The driver required for the CDC device is located on the included CD and is also available
on the TWR-SER2 webpage found at
www.freescale.com/tower
.
If needed the UART0 transceiver signals can be isolated from the Tower Elevator using J7.
Pins
Description
1-2
Remove to Isolate UART0_TX
3-4
Remove to Isolate UART0_RX
3.5.3
Additonal RS232 Interfaces
UART2 and UART3 (RXD/TXD/RTS/CTS) are connected to additional RS-232 transceivers. The RS-
232 transceivers are terminated to 2x5 headers (refer to table for pinout).
These interfaces are capable of utilizing the optional RTS/CTS signals for flow control.
J19 & J20
Pin #
Signal Name
1
NC
2
NC
3
RXD
4
RTS
5
TXD
6
CTS
7
NC
8
NC
9
GND
10
NC
