Rainbow Electronics MAX5945 - Manual (Page 25)

If the port remains in current limit or the PGOOD condi-
tion is not met at the end of the startup period, the port
shuts down and the corresponding STRT_FLT_ is set to
1. A 1 in any of the STRT_FLT_ bits forces R00h[6] to 1.
IVC_ is set to 1 whenever the port current exceeds the
maximum allowed limit for the class (determined during
the classification process). A 1 in any of IVC_ forces
R00h[6] to 1. When the CL_DISC (R17h[2]) is set to 1,
the port will also limit the load current according to its
class as specified in the Electrical Characteristics
table. As with any other events register, the startup
event register (Table 10) has two addresses. When
read through the R08h address, the content of the reg-
ister is left unchanged. When read through the CoR
R09h address, the register content will be cleared. A
reset sets R08h/R09h = 00h.
The MAX5945 continuously monitors the power supplies
and sets the appropriate bits in the supply event register
(Table 11). V
DD_OV / V EE_OV is set to 1 whenever V DD /
V EE exceeds its overvoltage threshold. V DD_UV / V EE_UV
is set to 1 whenever V
DD
/ V
EE
falls below its undervolt-
age threshold.
OSC_FAIL is set to 1 whenever the amplitude of the
oscillator signal at the OSC_input falls below a level
that might compromise the AC disconnect detection
MAX5945
Quad Network Power Controller
for Power-Over-LAN
______________________________________________________________________________________ 25
ADDRESS = 08h 09h
SYMBOL BIT R/W R/W
DESCRIPTION
IVC4 7 R CoR Class overcurrent flag for port 4
IVC3 6 R CoR Class overcurrent flag for port 3
IVC2 5 R CoR Class overcurrent flag for port 2
IVC1 4 R CoR Class overcurrent flag for port 1
STRT_FLT4 3 R CoR Startup failed on port 4
STRT_FLT3 2 R CoR Startup failed on port 3
STRT_FLT2 1 R CoR Startup failed on port 2
STRT_FLT1 0 R CoR Startup failed on port 1
Table 10. Startup Event Register
ADDRESS = 0Ah 0Bh
SYMBOL BIT R/W R/W
DESCRIPTION
TSD 7 R CoR Overtemperature shutdown
V DD_OV 6 R CoR V DD overvoltage condition
V DD_UV 5 R CoR V DD undervoltage condition
V EE_UVLO 4 R CoR V EE undervoltage lockout condition
V EE_OV 3 R CoR V EE overvoltage condition
V EE_UV 2 R CoR V EE undervoltage condition
OSC_FAIL 1 R CoR Oscillator amplitude is below limit
V DD_UVLO 0 R CoR V DD undervoltage lockout condition
Table 11. Supply Event Register
ADDRESS = 0Ch, 0Dh, 0Eh, 0Fh
SYMBOL BIT R/W
DESCRIPTION
Reserved 7 R Reserved
6 R CLASS_[2]
5 R CLASS_[1] CLASS_
4 R CLASS_[0]
Reserved 3 R Reserved
2 R DET_[2]
1 R DET_[1] DET_ST_
0 R DET_[0]
Table 12. Port Status Registers