Operation

STM6321/6322STM6821/6822/6823/6824/6825

12/29

Figure 12.

Figure 13.

1.

This configuration does not work on open drain outputs of the STM6321/6322/6822.

2.6

Interfacing to microprocessors with bidirectional reset pins

Microprocessors with bidirectional reset pins can contend with the STM6321 / 6322 / 6821 /

6822 / 6823 / 6824 / 6825 reset output. For example, if the reset output is driven high and the

microprocessor wants to pull it low, signal contention will result. To prevent this from

occurring, connect a 4.7 k

Ω resistor between the reset output and the microprocessor’s

reset I/O as in Figure 14.

Figure 14.

Interfacing to microprocessors with bidirectional reset I/O

AI09138

STM6XXX

RST

GND

R1

AI09139

STM6XXX

RST

GND

R1

AI09135

STM6XXX

RST

GND

4.7k

Microprocessor

RST

Buffered Reset to other

System Components

GND