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| Full-speed |  |  |  |  |  |  | ||||
| S/N | Operation Voltage | ROM Size(B) | RAM Size(B) | GPIOs | External Interrupts | 16/8-bit Timer | Built-in Regulator | Endpoints | USB Interfact | Package Type | 
| 1 | 2.7~3.6V | 16K(Max) | 256+576 | 36 | 4 | 3 | None | 4 | USB2.0 FS | LQFP48 | 
| 2 | 2.7~3.6V | 16K(Max) | 256 | 31 | 4 | 3 | None | 6 | USB2.0 FS | LQFP48 |