MAX5971BETI+ Maxim Integrated Products, MAX5971BETI+ Datasheet - Page 25

• Manufacturer Part Number: MAX5971BETI+
• Description: Hot Swap & Power Distribution IEEE 802.3af/at PSE Controller
• Manufacturer: Maxim Integrated Products

Specifications of MAX5971BETI+

• Lead Free Status / Rohs Status: Details

Any bytes received after the command byte are data
bytes. The first data byte goes into the internal register
of the MAX5971B selected by the command byte (Figure
12). The control byte address then autoincrements, if
possible (see Table 6), and then waits for the next data
byte or a STOP condition.
If multiple data bytes are transmitted before a STOP con-
dition is detected, these bytes are stored in subsequent
MAX5971B internal registers as the control byte address
autoincrements (Figure 13). If the control byte address
can no longer increment, any subsequent data sent con-
tinues to write to that address.
Figure 12. Write Format: Control and Single Data Byte Written
Figure 13. Write Format: Control and n Data Bytes Written
Figure 14. Read Format: Control and n Data Bytes Read
S
S
S
CONTROL BYTE STORED ON STOP CONDITION
CONTROL BYTE STORED ON STOP CONDITION
CONTROL BYTE STORED ON STOP CONDITION
ACKNOWLEDGE FROM THE MAX5971B
ACKNOWLEDGE FROM THE MAX5971B
ACKNOWLEDGE FROM THE MAX5971B
SLAVE ADDRESS
SLAVE ADDRESS
SLAVE ADDRESS
______________________________________________________________________________________
R/W
R/W
R/W
Single-Port, 40W, IEEE 802.3af/at,
0
0
0
ACK
ACK
ACK
CB7
CB7 CB6 CB5 CB4 CB3 CB2 CB1 CB0
CB7 CB6 CB5 CB4 CB3 CB2 CB1 CB0
CB6 CB5 CB4 CB3 CB2 CB1 CB0
ACKNOWLEDGE FROM THE MAX5971B
CONTROL BYTE
CONTROL BYTE
CONTROL BYTE
PSE Controller with I
A read command for the MAX5971B comprises the
device slave address transmission with the R/W bit set
to 1, followed by at least one byte of information. As
with a write command, the first byte of information is the
command byte. The MAX5971B then reads using the
internally stored command byte as an address pointer,
the same way the stored command byte is used as an
address pointer for a write. This pointer autoincrements
after reading each data byte using the same rules as for
a write, though the master now sends the acknowledge
bit after each read receipt (Figure 14). When performing
read-after-write verification, remember to reset the com-
mand byte’s address because the stored control byte
address autoincrements after the write.
ACK
ACK
ACK
D7
D7
D7
ACKNOWLEDGE FROM THE MAX5971B
ACKNOWLEDGE FROM THE MAX5971B
D6
D6
D6
ACKNOWLEDGE FROM THE MASTER
WORD ADDRESS AUTOINCREMENT
WORD ADDRESS AUTOINCREMENT
WORD ADDRESS AUTOINCREMENT
D5
D5
D5
DATA BYTE (n BYTES)
DATA BYTE (n BYTES)
DATA BYTE (1 BYTE)
Message Format for Reading
REPEAT FOR n BYTES
REPEAT FOR n BYTES
D4
D4
D4
D3
D3
D3
D2
D2
D2
D1
D1
D1
D0
D0
D0
ACK
ACK
ACK
2
P
P
P
C
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