PTB0/IRQ/TCLK1PTB1/RESET#2PTB2/BKGD/MS3PTB3/BLMS#4PTA0/KBIP0/TPMCH05NC6PTA1/KBIP1/MISO7PTA2/KBIP2/MOSI8PTA3/KBIP3/SPSCK9PTA4/KBIP4/SS#10VDD11NC12VSS13USBDN14USBDP15VUSB3316PTA5/KBIP5/TPMCH117NC18PTA6/KBIP6/RxD19PTA7/KBIP7/TxD20PTB4/XTAL21PTB5/EXTAL22VSSOSC23NC24EP25