DS80C390_00 Datasheet, PDF (75/155 Pages) Dallas Semiconductor – High-Speed Microcontroller User’s Guide Supplement

DS80C390 High-Speed Microcontroller User’s Guide Supplement
Watchdog Control (WDCON)
7
6
5
4
3
2
1
0
SFR D8h SMOD POR
EPF1
PFI
WDIF WTRF EWT
RWT
RW-0 RW-* RW-0 RW-* RW-0 RW-* RW-* RW-0
R=Unrestricted Read, W=Unrestricted Write, T=Timed Access Write Only ,
-n=Value after Reset, *=See Description
SMOD
Bit 7
POR
Bit 6
EPFI
Bit 5
PFI
Bit 4
Serial Modification. This bit controls the doubling of the serial port 1 baud rate
in modes 1, 2, and 3.
0 = Serial port 1 baud rate operates at normal speed
1 = Serial port 1 baud rate is doubled.
Power-on Reset Flag. This bit indicates whether the last reset was a power-on
reset. This bit is typically interrogated following a reset to determine if the reset
was caused by a power-on reset. It must be cleared by a Timed Access write
before the next reset of any kind or the software may erroneously determine that
another power-on reset has occurred. This bit is set following a power-on reset
and unaffected by all other resets. Note: This bit is not Timed Access protected
on the DS80C310.
0 = Last reset was from a source other than a power-on reset
1 = Last reset was a power-on reset.
Enable Power fail Interrupt. This bit enables/disables the ability of the internal
band-gap reference to generate a power-fail interrupt when V_CC falls below
approximately 4.5 volts. While in Stop mode, both this bit and the Band-gap
Select bit, BGS (EXIF.0), must be set to enable the power-fail interrupt.
0 = Power-fail interrupt disabled.
1 = Power-fail interrupt enabled during normal operation. Power-fail interrupt
enabled in Stop mode if BGS is set.
Power fail Interrupt Flag. When set, this bit indicates that a power-fail interrupt
has occurred. This bit must be cleared in software before exiting the interrupt
service routine, or another interrupt will be generated. Setting this bit in software
will generate a power-fail interrupt, if enabled.
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