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

Description

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1.1

Pin descriptions

1.1.1

Active-low, push-pull reset output (RST) - STM6822/6823/6824/6825

threshold, the watchdog triggers a reset, or MR goes from low to high.

1.1.2

Active-low, open drain reset output (RST) - STM6321/6322/6822

threshold, the watchdog triggers a reset, or MR goes from low to high. Connect a pull-up

resistor to supply voltage.

1.1.3

Push-button reset input (MR)

A logic low on MR asserts the reset output. Reset remains asserted as long as MR is low

be driven from a TTL or CMOS logic line, or shorted to ground with a switch. Leave open if

unused.

1.1.4

Watchdog input (WDI)

If WDI remains high or low for at least 1.6s, the internal watchdog timer expires and reset is

asserted. The internal watchdog timer clears while reset is asserted or when WDI sees a

rising or falling edge. The watchdog function CAN be disabled if WDI is left unconnected or

is connected to a tri-state buffer output.

1.1.5

Active-high reset output (RST)

Active-high, push-pull reset output; inverse of RST.

Table 3.

Pin functions

Pin

Name

Function

STM6822

STM6823

STM6821

STM6321

STM6824

STM6322

STM6825

1—

1

1

RST

Active-low reset output

33

—

4

MR

Push-button reset input

4

4

4

—

WDI

Watchdog Input

—

1

3

3

RST

Active-high reset output

55

5

5

Supply voltage

22

2

2

Ground