GPIO7/RIA#28GPIO6/CDA#27GPIO5/DTRA#26GPIO4/DSRA#25RXB24TXB23VSS22GPIO3/RIB#21GPIO2/CDB#20GPIO1/DTRB#19GPIO0/DSRB#18RTSB#17CTSB#16IRQ#15SDA/VSS14SCL/SCLK13n.c./SO12A1/SI11A0/CS#10I2C/SPI#9VDD8XTAL27XTAL16RESET#5RXA4TXA3CTSA#2RTSA#1