Datasheet

MCP40D17/18/19
DS22152B-page 40 © 2009 Microchip Technology Inc.
FIGURE 5-15: I
2
C Read Command Format (Slave Address = “0101110”).
FIGURE 5-16: I
2
C Read Communication Behavior (Slave Address = “0101110”).
STOP bit
Slave Address Byte
Command Code
1010S1100 0A000A
Slave Address Byte Data Byte
AD30 D6D5D4 D2D1D0A
(2)
P
Read/Write bit (“0” = Write)
00 00
11 01
01 01
S = Start Condition
P = Stop Condition
A = Acknowledge
X = Don’t Care
R/W
= Read/Write bit
D6:D0 = Data bits
Legend
S
Read/Write bit (“1” = Read)
Note 1: Master Device is responsible for ACK
/ NACK signal. If a NACK signal occurs, the MCP40D17/18/19 will
abort this transfer and release the bus.
2: The Master Device will Not ACK
, and the MCP40D17/18/19 will release the bus so the Master Device can
generate a Stop or Repeated Start condition.
Read 1 Byte with Command Code = 00h
Read 2 Byte with Command Code = 00h
S Slave Address
R
/
W
A
C
K Command Code
A
C
K
R
S Slave Address
R
/
W
A
C
K
Master S010111001000000001S010111011
MCP40D17/18/19 0 0 0
I
2
C Bus S010111000000000000S010111010
Data Byte
A
C
KP
Master 1 P
MCP40D17/18/19 0 d d d d d d d 1
I
2
C Bus 0ddddddd1P
S Slave Address
R
/
W
A
C
K Command Code
A
C
K
R
S Slave Address
R
/
W
A
C
K
Master S010111001000000001S010111011
MCP40D17/18/19 0 0 0
I
2
C Bus S010111000000000000S010111010
Data Byte
A
C
K Data Byte
A
C
KP
Master 0 1 P
MCP40D17/18/19 0ddddddd10ddddddd1
I
2
C Bus 0ddddddd00ddddddd1P