Microchip Technology dsPIC30F - Page 702

dsPIC30F Family Reference Manual
DS70074C-page 26-4 © 2004 Microchip Technology Inc.
A.2 Addressing I
2
C Devices
There are two address formats. The simplest is the 7-bit address format with a R/W
bit
(Figure A-2). The more complex is the 10-bit address with a R/W
bit (Figure A-3). For 10-bit
address format, two bytes must be transmitted. The first five bits specify this to be a 10-bit
address format. The 1st transmitted byte has 5 bits which specify a 10-bit address, the two
MSbs of the address, and the R/W
bit. The second byte is the remaining 8 bits of the address.
Figure A-2: 7-bit Address Format
Figure A-3: I
2
C 10-bit Address Format
S
R/W
ACK
Sent by
Slave
Slave Address
S
R/W
Read/Write pulse
MSb LSb
Start Condition
ACK
Acknowledge
S 1 1 1 1 0 A9 A8 R/W ACK A7 A6 A5 A4 A3 A2 A1 A0 ACK
Sent By Slave
= 0 for write
S
R/W
ACK
- Start Condition
- Read/Write Pulse
- Acknowledge