Power Management 14-3
14.03 POWER FAIL DETECTION CIRCUIT
The Power Failure Detector always monitors:
•
The backup battery to warn of a low battery condition, and
•
The +5V power supply to detect when it falls below 4.75V.
If either of the two above conditions occur, the PFO (Power Fail Output signal) goes
low. In the case of the +5V power supply, a reset will result as explained in the
previous section (14.02.2). In the case of the low battery, what happens will depend on
the setting of the W13 jumper and user-defined algorithm.
The W13 jumper, when shorted, will generate a NMI (Non Maskable Interrupt),
through the IOCHK* line, when the PFO goes low. In turn, this NMI may be serviced
by an interrupt handler to locate the source and notify the user or the system.
If the W13 jumper is left open, no NMI is generated, however an algorithm could be
used to detect a low battery condition and respond accordingly.
A low battery condition is detected, in any case, by polling bit 3 at TEKNOR’s I/O base
address register (190H, 290H or 390H, depending on W9 jumper setting): If this bit
reads “1”, then the battery voltage is good; if it reads “0”, then it is in a low condition
(below 2.9V, typical).
Jumper locations and settings are illustrated in Section 2.
Содержание PCI-993
Страница 31: ...Jumper Locations Configuration 2 7...
Страница 32: ...Jumper Locations Configuration 2 8 TABLE 2 1c Jumper Settings W13 W18 W22...
Страница 33: ...Jumper Locations Configuration 2 9 TABLE 2 1d Jumper Settings W24 W27 J14...
Страница 36: ...Connector Locations Pin Out 4 3 DIAGRAM 4 1 Connector Locations...
Страница 56: ...System 6 3 DIAGRAM 6 1 System Components Location Bottom of Board...
Страница 57: ...System 6 5 DIAGRAM 6 2 System Components Location Top of Board...
Страница 117: ...Video 13 2 DIAGRAM 13 1 Video Components Location Top of Board DIAGRAM 13 2 Video Components Location Bottom of Board...
Страница 127: ...PART THREE SOFTWARE REFERENCE 15 AMIBIOS SETUP 16 VIP UP SETUP 17 UPDATING BIOS WITH UBIOS 18 VT100 MODE...
Страница 172: ...VT100 Mode 18 3 DIAGRAM 18 1 VT100 Full Setup DIAGRAM 18 2 VT100 Partial Setup...
Страница 188: ...TEK933 Board Diagrams C 3 DIAGRAM C 1 TEK933 Assembly Top...
Страница 189: ...TEK933 Board Diagrams C 5 DIAGRAM C 2 TEK933 Assembly Bottom...
Страница 190: ...TEK933 Board Diagrams C 7 DIAGRAM C 3 TEK933 Configuration...
Страница 191: ...TEK933 Board Diagrams C 9 DIAGRAM C 4 TEK933 Mechanical Specifications...
Страница 197: ...Post Codes Error Codes E 2 to main BIOS in shadow RAM...