Operation
STM632x, STM682x
Figure 12. Ensuring RST valid to VCC = 0, (active low push-pull outputs)
STM6XXX
GND
VCC
RST
VCC
R1
AI09138
Figure 13. Ensuring RST valid to VCC = 0, (active high, push-pull outputs)
STM6XXX
GND
VCC
RST
VCC
R1
AI09139
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 kΩ 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
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DocID11110 Rev 13