MAX5945 datasheet(21/44 Pages) MAXIM

21 / 44 page

Message Format for Writing the MAX5945

A write to the MAX5945 comprises of the MAX5945’s

slave address transmission with the R/W bit set to 0, fol-

lowed by at least one byte of information. The first byte

of information is the command byte (Figure 11). The

command byte determines which register of the

MAX5945 is written to by the next byte, if received. If

the MAX5945 detects a STOP condition after receiving

the command byte, then the MAX5945 takes no further

action beyond storing the command byte. Any bytes

received after the command byte are data bytes. The

first data byte goes into the internal register of the

MAX5945 selected by the command byte. If the

MAX5945 transmits multiple data bytes before the

MAX5945 detects a STOP condition, these bytes store

in subsequent MAX5945 internal registers because the

control byte address auto-increments.

Any bytes received after the control byte are data

bytes. The first data byte goes into the internal register

of the MAX5945 selected by the control byte (Figure 8).

If multiple data bytes are transmitted before a STOP

condition is detected, these bytes are stored in subse-

quent MAX5945 internal registers because the control

byte address auto-increments.

Quad Network Power Controller

for Power-Over-LAN

______________________________________________________________________________________

Figure 11. Control Byte Received

SLAVE ADDRESS

CONTROL BYTE

ACKNOWLEDGE FROM MAX5945

D15

D14

D13

D12

D11

D10

CONTROL BYTE IS STORED ON RECEIPT OF STOP CONDITION

R/W

Figure 12. Control and Single Data Byte Received

SLAVE ADDRESS

CONTROL BYTE

DATA BYTE

ACKNOWLEDGE FROM MAX5945

1 BYTE

AUTO-INCREMENT

MEMORY WORD ADDRESS

D15 D14 D13 D12 D11 D10

HOW CONTROL BYTE AND DATA BYTE MAP

INTO THE REGISTER

ACKNOWLEDGE FROM MAX5945

R/W

Figure 13. ‘n’ Data Bytes Received

SLAVE ADDRESS

CONTROL BYTE

DATA BYTE

ACKNOWLEDGE FROM MAX5945

n BYTES

AUTO-INCREMENT

MEMORY WORD ADDRESS

D15 D14 D13 D12 D11 D10

HOW CONTROL BYTE AND DATA BYTE MAP

INTO THE REGISTER

ACKNOWLEDGE FROM MAX5945

R/W

MAX5945 Datasheet(PDF) 21 Page - Maxim Integrated Products

MAX5945 Datasheet(HTML) 21 Page - Maxim Integrated Products

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44

Datasheet Download

Link URL