ADUC843BSZ62-5 Datasheet, PDF (48/88 Pages) Analog Devices – MicroConverter® 12-Bit ADCs and DACs with Embedded High Speed 62-kB Flash MCU

ADuC841/ADuC842/ADuC843
I²C COMPATIBLE INTERFACE
The ADuC841/ADuC842/ADuC843 support a fully licensed
I²C serial interface. The I²C interface is implemented as a full
hardware slave and software master. SDATA is the data I/O pin,
and SCLOCK is the serial clock. These two pins are shared with
the MOSI and SCLOCK pins of the on-chip SPI interface. To
enable the I²C interface, the SPI interface must be turned off
(see SPE in Table 18) or the SPI interface must be moved to
P3.3, P3.4, and P3.5 via the CFG841.1/CFG842.1 bit. Application
Note uC001 describes the operation of this interface as imple-
mented and is available from the MicroConverter website at
www.analog.com/microconverter.
Three SFRs are used to control the I²C interface and are
described in the following tables.
I2CCON
I²C Control Register
SFR Address
E8H
Power-On Default
00H
Bit Addressable
Yes
Table 19. I2CCON SFR Bit Designations, Master Mode
Bit No. Name Description
7
MDO
I²C Software Master Data Output Bit (Master Mode Only).
This data bit is used to implement a master I²C transmitter interface in software. Data written to this bit is output on
the SDATA pin if the data output enable (MDE) bit is set.
6
MDE
I²C Software Master Data Output Enable Bit (Master Mode Only).
Set by the user to enable the SDATA pin as an output (Tx).
Cleared by the user to enable the SDATA pin as an input (Rx).
5
MCO
I²C Software Master Clock Output Bit (Master Mode Only).
This data bit is used to implement a master I²C transmitter interface in software. Data written to this bit is output on
the SCLOCK pin.
4
MDI
I²C Software Master Data Input Bit (Master Mode Only).
This data bit is used to implement a master I²C receiver interface in software. Data on the SDATA pin is latched into
this bit on SCLOCK if the data output enable (MDE) bit is 0.
3
I2CM
I²C Master/Slave Mode Bit.
Set by the user to enable I²C software master mode.
Cleared by the user to enable I²C hardware slave mode.
2
----
Reserved.
1
----
Reserved.
0
----
Reserved.
Table 20. I2CCON SFR Bit Designations, Slave Mode
Bit No. Name Description
7
I2CSI
I²C Stop Interrupt Enable Bit.
Set by the user to enable I²C stop interrupts. If set, a stop bit that follows a valid start condition generates an
interrupt.
Cleared by the user to disable I²C stop interrupts.
6
I2CGC I²C General Call Status Bit.
Set by hardware after receiving a general call address.
Cleared by the user.
5
I2CID1 I²C Interrupt Decode Bits.
4
I2CID0 Set by hardware to indicate the source of an I²C interrupt.
00 Start and Matching Address.
01 Repeated Start and Matching Address.
10 User Data.
11 Stop after a Start and Matching Address.
3
I2CM
I²C Master/Slave Mode Bit.
Set by the user to enable I²C software master mode.
Cleared by the user to enable I²C hardware slave mode.
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