MIC2358 Datasheet, PDF (25/29 Pages) Micrel Semiconductor – IEEE 802.3af Octal Power Sourcing Equipment Controller

Micrel, Inc.
Global Status Register
SMBus Address: 0x45
Read Only
Bit 7
Bit 6
–
–
Bit 5
–
Bit 4
–
Bit 3
–
Bit 2
UVP
Bit 1
OVP
MIC2358YLQ
Bit 0
spm_fault
Name
spm_fault
OVP
UVP
Description
Set when the port has requested more power than is available as indicated by the shared power management
controller. The port state machine will transition to the POWER_DENIED state.
Set when the power supply exceeds Global Overvoltage Protection Threshold Voltage VGOVP.
Set when the power supply drops off below Global Undervoltage Protection Threshold Voltage VGUVP.
Global Current_Port Register
SMBus Address: 0x46
Read Only
Bit 7
–
Bit 6
–
Bit 5
–
Bit 4
–
Bit 3
–
Bit 2
Bit 1
current_port
Bit 0
Name
current_port
Description
Indicates which port is currently being managed by the chip. Possible values are shown below.
Ports
Status
Value
Port 1
000
Port 2
001
Port 3
010
Port 4
011
Port 5
100
Port 6
101
Port 7
110
Port 8
111
Note:
1. The MIC2358YLQ implements a single ADC to service all ports during detection, classification, measurement of port output voltage and current.
The current_port indicates which particular port is being serviced. This register allows the host with capability to monitor internal ports activity
timing.
Global Detect_Min Register
SMBus Address: 0x48
Read and Write
This register is used to program the lower limit of acceptable resistor values for detecting a powered device. The weighting is 400Ω
and the default value is 40 dec (0x28 hex). The default value of 40 means the lower limit is 40 x 400 = 16000Ω. Setting this register
to a different value could cause operation that does not comply with IEEE Std 802.3af-2003.
July 2010
25
M9999-070810