70291E Datasheet, PDF (233/436 Pages) Microchip Technology – High-Performance, 16-bit Digital Signal Controllers

dsPIC33FJ32MC302/304, dsPIC33FJ64MCX02/X04 AND dsPIC33FJ128MCX02/X04
19.0 INTER-INTEGRATED
CIRCUIT™ (I²C™)
Note 1: This data sheet summarizes the fea-
tures of the dsPIC33FJ32MC302/304,
dsPIC33FJ64MCX02/X04
and
dsPIC33FJ128MCX02/X04 family of
devices. It is not intended to be a
comprehensive reference source. To
complement the information in this data
sheet, refer to “Section 19.
Inter-Integrated Circuit™ (I²C™)”
(DS70195) of the “dsPIC33F/PIC24H
Family Reference Manual”, which is
available from the Microchip web site
(www.microchip.com).
2: Some registers and associated bits
described in this section may not be
available on all devices. Refer to
Section 4.0 “Memory Organization” in
this data sheet for device-specific register
and bit information.
The Inter-Integrated Circuit (I²C) module provides
complete hardware support for both Slave and
Multi-Master modes of the I²C serial communication
standard, with a 16-bit interface.
The I²C module has a 2-pin interface:
• The SCLx pin is clock.
• The SDAx pin is data.
The I²C module offers the following key features:
• I²C interface supporting both Master and Slave
modes of operation
• I²C Slave mode supports 7-bit and 10-bit
addressing
• I²C Master mode supports 7-bit and 10-bit
addressing
• I²C port allows bidirectional transfers between
master and slaves
• Serial clock synchronization for I²C port can be
used as a handshake mechanism to suspend and
resume serial transfer (SCLREL control)
• I²C supports multi-master operation, detects bus
collision and arbitrates accordingly
19.1 Operating Modes
The hardware fully implements all the master and slave
functions of the I²C Standard and Fast mode
specifications, as well as 7 and 10-bit addressing.
The I²C module can operate either as a slave or a
master on an I²C bus.
The following types of I²C operation are supported:
• I²C slave operation with 7-bit addressing
• I²C slave operation with 10-bit addressing
• I²C master operation with 7-bit or 10-bit addressing
For details about the communication sequence in each
of these modes, refer to the “dsPIC33F/PIC24H Family
Reference Manual”. Please see the Microchip web site
(www.microchip.com) for the latest dsPIC33F/PIC24H
Family Reference Manual chapters.
19.2 I²C Registers
I2CxCON and I2CxSTAT are control and status
registers, respectively. The I2CxCON register is
readable and writable. The lower six bits of I2CxSTAT
are read-only. The remaining bits of the I2CSTAT are
read/write:
• I2CxRSR is the shift register used for shifting data
internal to the module and the user application
has no access to it
• I2CxRCV is the receive buffer and the register to
which data bytes are written, or from which data
bytes are read
• I2CxTRN is the transmit register to which bytes
are written during a transmit operation
• The I2CxADD register holds the slave address.
• A status bit, ADD10, indicates 10-bit Address
mode
• The I2CxBRG acts as the Baud Rate Generator
(BRG) reload value
In receive operations, I2CxRSR and I2CxRCV together
form a double-buffered receiver. When I2CxRSR
receives a complete byte, it is transferred to I2CxRCV,
and an interrupt pulse is generated.
© 2011 Microchip Technology Inc.
DS70291E-page 233