MIC2593 Micrel Semiconductor, MIC2593 Datasheet - Page 19

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

Status Register Slot B (STATB)
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 /FAULTB pin is not affected by reading the Status Register or by clearing active status bits.
Notes:
1.
2.
April 2004
MIC2593
read-only
VAUXBF
12VMBF
FAULTB
FAULTB
VAUXB
MAINB
12VBF
If FAULTB has been set by an overcurrent condition on one or more of the MAIN outputs, the ONB input must go LOW to reset FAULTB.
If FAULTB has been set by a VAUXB overcurrent event, the AUXENB input must go LOW to reset FAULTB.
If an overcurrent has occurred on both a MAIN output and the VAUX output of slot B, both ONB and AUXENB of the slot must go low to reset
FAULTB.
Neither the FAULTB bit nor the /FAULTB pin is active when the MIC2593 power paths are controlled by the System Management Interface. When
using SMI power path control, the AUXENB and ONB pins for that slot must be tied to GND.
Bit(s)
5VBF
3VBF
D[7]
Power-Up Default Value: 0000 0000
Command_Byte Value (R/W): 0000 0101
FAULT Pin Status – Slot B
MAIN Enable Status – Slot B
VAUX Enable Status – Slot B
Overcurrent Fault: VAUXB supply B
Overcurrent Fault: –12V supply B
Overcurrent Fault: +12V supply B
Overcurrent Fault: 5V supply B
Overcurrent Fault: 3.3V supply B
read-only
MAINB
D[6]
h
. Both slots are disabled upon power-up, i.e., all supply outputs are off. In response to an
read-only
VAUXB
Function
D[5]
Status Register, Slot B (STATB)
b
= 00
b
h
= 05
read/write
VAUXBF
D[4]
h
19
read/write
12MVBF
D[3]
1 = /FAULTB pin asserted
(/FAULTB pin is LOW)
0 = /FAULTB pin de-asserted
(/FAULTB pin is HIGH)
See Notes 1 and 2
Represents the actual state (on/off) of the
four Main Power outputs for Slot B
(+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 B
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
12VBF
D[2]
Operation
read/write
5VBF
D[1]
read/write
M9999-042204
3VBF
D[0]
Micrel