Zilog Z8F0411 User Manual
Page 55
MDS General-Purpose Board Development Kit
User Manual
UM016905-1207
Appendix—MDS-PM Board Pin Maps
44
I
2
C Bus Expander U2 Signals For Serial Port Control
U2 is an I
2
C bus expander that can be used via software to control the
signals on jumper J2. If the U2 I
2
C expander is to be used, ensure all
jumpers are removed from J2. U2 powers up with all pins in input mode.
The U2 bus expander I
2
C address is 0100010 R/W.
•
GPS_ENABLE—D0 = 0
•
IrDA ENABLE—D1 = 0
•
RS485 ENABLE—D2 = 0
•
RS232_COM1_ENABLE—D3 = 0
•
RS232_COM2_ENABLE—D4 = 0
•
RF_ENABLE—D5 = 0
•
SW_UART_ENABLE—D6 = 0
•
Spare—D7
RS232-1 Signals
Enabled by jumper on J2 pins 1, 2, or by U2 pin D3. Uses COM1. When
enabled, disables RS485, IrDA, and RF.
•
TXD—PA5_TXD0
•
RXD—PA4_RXD0
•
CTS—PA3_CTS0 (Input)
•
RTS—PG0 (Software RTS0 Output)