Try this:
avrdude -c usbtiny -p m644p -U lfuse:w:0xFF:m -U hfuse:w:0xD6:m -U efuse:w:0xFF:m
A blank ATmega chip is set to run on internal 1MHz clock. The above sets the fuse bits to use external crystal clock. Since you don’t have CH340G yet, you don’t need to flash the bootloader.
