Freescale Semiconductor M9328MX21ADSE - Manual (Page 48)

Support Information
M9328MX21ADSE User’s Manual, Rev. A
3-20 Freescale Semiconductor
3.4.3 External UART Connector
Connector P3 is connected to Port A of U17, an Exar ST16C255 DUART. This female DB9 connector is
configured for RS-232 Data Communications Equipment (DCE) operation. Figure 3-7 shows the pin
assignments and Table 3-7 provides signal descriptions for the connector.
Figure 3-7. Connector P3 (EXT UART) DCE Pin Assignments
3.5 Multi-ICE Connector
Connector P20 is the ADS Multi-ICE connector. Figure 3-8 shows pin assignments and Table 3-8 provides
signal descriptions for the connector.
Figure 3-8. Multi-ICE Connector P20 (on the CPU) Pin Assignments
Table 3-7. Connector P3 (EXT UART) DCE Signal Descriptions
Pin(s) Signal Description
1 CD CARRIER DETECT — RS-232 output signal, pulled active positive
2 TXD TRANSMITTED DATA — RS-232 serial data output signal
3 RXD RECEIVED DATA – RS-232 serial data input signal
4 DTR
DATA TERMINAL READY — RS-232 serial data input signal, the logic level signal is
available at TP9
5 GND GROUND
6 DSR DATA SET READY — RS-232 output signal, pulled active positive
7 RTS READY TO SEND — RS-232 input signal, active positive,
8 CTS CLEAR TO SEND — RS-232 output signal, active positive,
9 RI RING INDICATOR — RS-232 output signal, forced inactive negative
P20
VCC 1 • • 2 VCC
TRST_B 3 • • 4 GND
TDI 5 • • 6 GND
TMS 7 • • 8 GND
TCK 9 • • 10 GND
RTCK 11 • • 12 GND
TDO 13 • • 14 GND
RESET_IN_B 15 • • 16 GND
NC 17 • • 18 GND
NC 19 • • 20 GND
1
RX
D
TX
D
RI
CT
S
RT
S
DS
R
P3
2 3 4 5
9 8 7 6
DT
R
G
ND
CD