MAX5971B Maxim Integrated Products, MAX5971B Datasheet - Page 32

• Manufacturer Part Number: MAX5971B
• Description: PSE Controller
• Manufacturer: Maxim Integrated Products

Single-Port, 40W, IEEE 802.3af/at,
PSE Controller with I
The disconnect enable register (R13h, Table 20) is used
to enable AC and DC load-disconnect detection. On
power-up or after a reset condition, this register is reset to
a default value of 000x to 000x, where the status latched
in from the OSC input determines if AC or DC disconnect
is set (see the AC/DC Disconnect Monitoring sections
for details). Setting DCD_EN (R13h[0]) to 1 enables the
DC load-disconnect detection feature. Setting ACD_EN
(R13h[4]) to 1 enables the AC load-disconnect feature.
If enabled, the load-disconnect detection starts during
power mode and after startup when the PGOOD bit
(R10h[4], Table 16) goes high.
Table 20. Disconnect Enable Register
Table 21. Detection And Classification Enable Register
32
CLASS_EN
SYMBOL
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
SYMBOL
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
ACD_EN
DCD_EN
DET_EN
_____________________________________________________________________________________
ADDRESS = 13h
ADDRESS = 14h
BIT NO.
BIT NO.
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
Disconnect Enable Register (R13h)
TYPE
TYPE
R/W
R/W
R/W
R/W
—
—
—
—
—
—
—
—
—
—
—
—
Reserved
Reserved
Reserved
Enable AC disconnect detection on the port
Reserved
Reserved
Reserved
Enable DC disconnect detection on the port
Reserved
Reserved
Reserved
Enable classification on the port
Reserved
Reserved
Reserved
Enable detection on the port
2
C
The detection and classification enable register (R14h,
Table 21) is used to enable detection and classification
routines for the port. On a power-up or after a reset con-
dition, this register is set to a default value of FFh (which
corresponds to the default auto mode). Setting DET_EN
(R14h[0]) and CLASS_EN (R14h[4]) to 1 enables load
detection and classification, respectively. Detection
always has priority over classification. For classifica-
tion without detection, set the DET_EN bit to 0 and the
CLASS_EN bit to 1.
When entering auto mode, R14h defaults to FFh. When
entering semi or manual modes, R14h defaults to 00h.
In manual mode, R14h works like a pushbutton. Set the
bits high to launch the corresponding routine. The bit
then clears after one complete detection or classification
cycle finishes.
DESCRIPTION
DESCRIPTION
Detection and Classification
Enable Register (R14h)