Operation

M40SZ100Y, M40SZ100W

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2.2

Power-on reset output

All microprocessors have a reset input which forces them to a known state when starting.

(see Table 7 on page 17). This signal is an open drain configuration. An appropriate pull-up

2.3

Reset input (RSTIN)

The M40SZ100Y/W provides one independent input which can generate an output reset.

The duration and function of this reset is identical to a reset generated by a power cycle.

Table 3 and Figure 8 illustrate the AC reset characteristics of this function. Pulses shorter

100k

Ω resistor.

Figure 8.

RSTIN timing waveform

1.

With pull-up resistor

Table 3.

Reset AC characteristics

2.4

Battery low pin

The M40SZ100Y/W automatically performs battery voltage monitoring upon power-up, and

at factory-programmed time intervals of at least 24 hours. The Battery Low (BL) pin will be

asserted if the battery voltage is found to be less than approximately 2.5V. The BL pin will

remain asserted until completion of battery replacement and subsequent battery low

monitoring tests, either during the next power-up sequence or the next scheduled 24-hour

interval.

Symbol

1.

Min

Max

Unit

(2)

2.

Pulse width less than 50ns will result in no RESET (for noise immunity).

RSTIN low to RSTIN high

200

ns

(3)

3.

RSTIN high to RST high

40

200

ms

AI04768

RST

(1)

RSTIN

tRLRH

tR1HRH