MIC2591B_05 Datasheet, PDF (29/34 Pages) Micrel Semiconductor – Dual-Slot PCI Express Hot-Plug Controller

MIC2591B
Common Status Register (CS)
8-Bits, Read/Write
D[7]
read-write
Reserved
D[6]
read-write
Reserved
Common Status Register (CS)
D[5]
D[4]
D[3]
read-only
read-only
read-write
GPI_B0
GPI_A0
INTMSK
D[2]
read-write
UV_INT
Micrel
D[1]
read-write
OT_INT
D[0]
read-only
Reserved
Bit(s)
D[7]
D[6]
GPI_B0
GPI_A0
INTMSK
Function
Reserved
Reserved
General Purpose Input 0, Slot B
General Purpose Input 0, Slot A
Interrupt Mask
UV_INT Undervoltage Interrupt
OT_INT Overtemperature Interrupt
D[0]
Reserved
Operation
Always read as zero
Always read as zero
State of GPI_B0 pin
State of GPI_A0 pin
0 = /INT generation is enabled
1 = /INT generation is disabled. The
MIC2591B does not participate in the SMBus
Alert Response Address (ARA) protocol
0 = No UVLO fault
1 = UVLO fault
Set whenever a circuit breaker fault condition
occurs as a result of an undervoltage lockout
condition on one of the main supply inputs.
This bit is only set if a UVLO condition occurs
while the ON[A/B] pin is asserted or the
MAIN[A/B] control bits are set
0 = Die Temp < 160°C.
1 = Fault: Die Temp > 160°C.
Set if a fault occurs as a result of the
MIC2591B’s die temperature exceeding
160°C
Undefined
Power-Up Default Value:
Command_Byte Value (R/W):
00000000_b = 00_h
00000110_b = 06_h
To reset the OT_INT and UV_INT fault bits, a logical 1 must be written back to these bits.
March 2005
29
M9999-033105