MAX5935CAX Maxim Integrated Products, MAX5935CAX Datasheet - Page 31

• Manufacturer Part Number: MAX5935CAX
• Description: Hot Swap & Power Distribution
• Manufacturer: Maxim Integrated Products

Specifications of MAX5935CAX

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Table 23. ID Register
ID register keeps track of the device ID number and revision. The MAX5935’s ID_CODE[4:0] = 11000b. Contact the factory for
REV[2:0] value.
Table 24. SMODE Register
Enable SMODE function (Table 24) by setting
EN_WHDOG (R1Fh[7]) to 1. SMODE_ bit goes high when
the watchdog counter reaches zero and the port(s)
switch over to hardware-controlled mode. SMODE_ also
goes high each and every time the software tries to
power on a port but is denied since the port is in hard-
ware mode. A reset sets R1Ch = 00h.
Set EN_WHDOG (R1Fh[7]) to 1 (Table 25) to enable the
watchdog function. When activated, the watchdog timer
counter, WDTIME[7:0], continuously decrements toward
zero once every 164ms. Once the counter reaches zero
(also called watchdog expiry), the MAX5935 enters hard-
ware-controlled mode and each port shifts to a mode set
by the HWMODE_ bit in register R1Fh (Table 24). Use
software to set WDTIME and continuously set this register
to some nonzero value before the register reaches zero to
prevent a watchdog expiry. In this way, the software
gracefully manages the power to ports upon a system
crash or switchover.
Reserved
Reserved
Reserved
Reserved
SMODE4
SMODE3
SMODE2
SMODE1
SYMBOL
ID_CODE
SYMBOL
REV
ADDRESS = 1Bh
ADDRESS = 1Ch
BIT
7
6
5
4
3
2
1
0
BIT
______________________________________________________________________________________
7
6
5
4
3
2
1
0
CoR
CoR
CoR
CoR
CoR
—
—
—
—
R/W
R
R
R
R
R
R
R
R
Reserved
Reserved
Reserved
Reserved
Hardware control flag for port 4
Hardware control flag for port 3
Hardware control flag for port 2
Hardware control flag for port 1
ID_CODE[4]
ID_CODE[3]
ID_CODE[2]
ID_CODE[1]
ID_CODE[0]
REV [2]
REV [1]
REV [0]
Quad Network Power Controller
While in hardware-controlled mode, the MAX5935
ignores all requests to turn the power on and the flag
SMODE_ indicates that the hardware took control of the
MAX5935 operation. In addition, the software is not
allowed to change the mode of operation in hardware-
controlled mode. A reset sets R1Eh = 00h.
Setting EN_WHDOG (Table 26) high activates the
watchdog counter. When the counter reaches zero, the
port switches to the hardware-controlled mode deter-
mined by the corresponding HWMODE_ bit. A low in
HWMODE_ switches the port into shutdown by setting
the bits in register R12h to 00. A high in HWMODE_
switches the port into auto mode by setting the bits in
register R12h to 11. If WD_INT_EN is set, an interrupt is
sent if any of the SMODE bits are set.
DESCRIPTION
DESCRIPTION
for Power-Over-LAN
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