MIC2593 Micrel Semiconductor, MIC2593 Datasheet - Page 18

• Manufacturer Part Number: MIC2593
• Description: Dual-Slot PCI Hot Plug Controller
• Manufacturer: Micrel Semiconductor

MIC2593
Status Register Slot A (STATA)
8-Bits, Read-Only
The power-up default value is 00
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:
2.
M9999-042204
1.
read-only
VAUXAF
12MVAF
FAULTA
FAULTA
VAUXA
MAINA
12VAF
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.
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.
Bit(s)
5VAF
3VAF
D[7]
Power-Up Default Value: 0000 0000
Command_Byte Value (R/W): 0000 0100
FAULT Status – Slot A
MAIN Enable Status – Slot A
VAUX Enable Status – Slot A
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
read-only
MAINA
D[6]
h
. Both slots are disabled upon power-up, i.e., all supply outputs are off. In response to an
read-only
VAUXA
Function
D[5]
Status Register, Slot A (STATA)
b
= 00
b
h
= 04
read/write
VAUXAF
D[4]
h
18
read/write
12MVAF
D[3]
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
read/write
12VAF
D[2]
Operation
read/write
5VAF
D[1]
read/write
3VAF
April 2004
D[0]
Micrel