... circuit is sample,Low power cost,With stable performance , it can meet the technology demand of Hign tech ,market products (with ... .2.Inbuilt resonator ,inbuilt transistor .3.12 I/O ports ,can support 66 keys.4.With adjustable frequency and driving current ... .5.1K ROM ,Can repeatedly flash and write for many times ,can be flashed online.6.Working Voltage:1 ...