STM6821 STMicroelectronics, STM6821 Datasheet - Page 12

• Manufacturer Part Number: STM6821
• Description: Reset + Watchdog
• Manufacturer: STMicroelectronics

Operation
2.6
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Figure 12. Ensuring RST valid to V
Figure 13. Ensuring RST valid to V
1. This configuration does not work on open drain outputs of the STM6321/6322/6822.
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. Interfacing to microprocessors with bidirectional reset I/O
Figure
14.
Doc ID 11110 Rev 11
GND
GND
STM6XXX
STM6XXX
CC
CC
= 0, (active-low push-pull outputs)
= 0, (active-high, push-pull outputs)
STM6321/6322STM6821/6822/6823/6824/6825
V
RST
V
RST
CC
CC
V
V
CC
CC
R1
R1
AI09138
AI09139