The TPI physical layer handles the basic low-level serial communication. The TPI physical layer uses a bi-directional, half-duplex serial receiver and transmitter. The physical layer includes serial-to-parallel and parallel-to-serial data conversion, start-of-frame detection, frame error detection, parity error detection, parity generation and collision detection.
The TPI is accessed via three pins, as follows:
- RESET: Tiny Programming Interface enable input
- TPICLK: Tiny Programming Interface clock input
- TPIDATA: Tiny Programming Interface data input/output
In addition, the VCC and GND pins must be connected between the external programmer and the device.
Figure 1. Using an External Programmer for
In-System Programming via TPI
NVM can be programmed at 5V, only. In some designs it may be necessary to protect components that can not tolerate 5V with, for example, series resistors.