Hardware interface

PM0083

4/13

DocID018532 Rev 3

1.3

Voltage levels for option programming and reading

The following table gives the voltage specifications. It is recommended to use the typical

values when designing a programming tool.

Caution:

All I/Os must have the same voltage level as VDD.

During option programming, the supply voltage of the STM8T143 is raised to 6.5 V. It is

recommended to make sure that the I/Os of the programmer can operate at 6.5 V.

1.4

In-circuit programming

When programming the device directly on the application board, the communication lines

must be directly connected to the device (not through CX resistor for example).

Furthermore, in case of In Circuit Programming, the programming tools user manual must

contain the maximum load current permitted to drive the application without disturbing the

programming signals.

Table 1. Voltages for reading or programming

VDD pin

Min

Typ

Max

Units

Programming mode entry

2.8

5.0

5.5

V

Option byte programming

6.4

6.5

6.6

Option byte reading

2.8

5.0

5.5