MIC2593 Datasheet, PDF (18/26 Pages) STMicroelectronics – Dual-Slot PCI Hot Plug Controller

MIC2593
Status Register Slot A (STATA)
8-Bits, Read-Only
Status Register, Slot A (STATA)
D[7]
D[6]
D[5]
D[4]
D[3]
read-only
read-only
read-only
read/write read/write
FAULTA
MAINA
VAUXA
VAUXAF
12MVAF
D[2]
read/write
12VAF
Micrel
D[1]
read/write
5VAF
D[0]
read/write
3VAF
Bit(s)
Function
FAULTA FAULT Status – Slot A
MAINA MAIN Enable Status – Slot A
VAUXA VAUX Enable Status – Slot A
VAUXAF
12MVAF
12VAF
5VAF
3VAF
Overcurrent Fault: VAUXA supply A
Overcurrent Fault: –12V supply A
Overcurrent Fault: +12V supply A
Overcurrent Fault: 5V supply A
Overcurrent Fault: 3.3V supply A
Operation
1 = /FAULTA pin asserted
(/FAULTA pin is LOW)
0 = /FAULTA pin de-asserted
(/FAULTA pin is HIGH)
See Notes 1 and 2
Represents the actual state (on/off) of the
four Main Power outputs for Slot A
(+12V, –12V, +5V and +3.3V)
1 = Main Power ON
0 = Main Power OFF
Represents the actual state (on/off) of the
Auxiliary Power output for Slot A
1 = AUX Power ON
0 = AUX Power OFF
1 = Fault 0 = No fault
1 = Fault 0 = No fault
1 = Fault 0 = No fault
1 = Fault 0 = No fault
1 = Fault 0 = No fault
Power-Up Default Value: 0000 0000_b = 00_h
Command_Byte Value (R/W): 0000 0100_b = 04_h
The power-up default value is 00_h. Both slots are disabled upon power-up, i.e., all supply outputs are off. In response to an
overcurrent fault condition, writing a logical 1 back into the active (or set) bit position will clear the bit and de-assert /INT. The
status of the /FAULTA pin is not affected by reading the Status Register or by clearing active status bits.
Notes:
1. If FAULTA has been set by an overcurrent condition on one or more of the MAIN outputs, the ONA input must go LOW to reset FAULTA.
If FAULTA has been set by a VAUXA overcurrent event, the AUXENA input must go LOW to reset FAULTA.
If an overcurrent has occurred on both a MAIN output and the VAUX output of slot A, both ONA and AUXENA of the slot must go low to reset
FAULTA.
2. Neither the FAULTA bit nor the /FAULTA pin is active when the MIC2593 power paths are controlled by the System Management Interface. When
using SMI power path control, AUXENA and ONA pins for that slot must be tied to GND.
M9999-042204
18
April 2004