Datasheet

ST72321Rx ST72321ARx ST72321Jx

190/193

To identify these parts, check the internal sales

type on the box label or the trace code marking on

the package.

15.4 LIMITATIONS SPECIFIC TO ROM

DEVICES

15.4.1 LVD Operation

Depending on the operating conditions, especially

the V

ramp up speed and ambient temperature,

in some cases the LVD may not start. When this

occurs, the MCU may operate outside the guaran-

teed functional area (see datasheet Figure 76)

without being forced into reset state.

In this case, proper use of the watchdog may

make it possible to recover through a watchdog re-

set and allow normal operations to resume.

Consequently, the LVD function is not guaranteed

in the current silicon revision. For complete securi-

ty, an external reset circuit must be added.

Rev Internal Salestype Trace Code

Rev Q

72F321xxx$A2

72F321xxx$U2

813xxxQ

Rev S

72F321xxx$A8

72F321xxx$U8

813xxxS

Rev 9 (full

spec)

72F321xxx$A3

72F321xxx$U3

813xxx9