I2C Registers
21.4.1.19 I2C_CON Register (offset = A4h) [reset = 0h]
I2C_CON is shown in
and described in
.
During an active transfer phase (between STT having been set to 1 and reception of ARDY), no
modification must be done in this register (except STP enable). Changing it may result in an unpredictable
behavior.
Figure 21-34. I2C_CON Register
31
30
29
28
27
26
25
24
Reserved
R-0h
23
22
21
20
19
18
17
16
Reserved
R-0h
15
14
13
12
11
10
9
8
I2C_EN
Reserved
OPMODE
STB
MST
TRX
XSA
R/W-0h
R-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
7
6
5
4
3
2
1
0
XOA0
XOA1
XOA2
XOA3
Reserved
STP
STT
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R-0h
R/W-0h
R/W-0h
LEGEND: R/W = Read/Write; R = Read only; W1toCl = Write 1 to clear bit; -n = value after reset
Table 21-27. I2C_CON Register Field Descriptions
Bit
Field
Type
Reset
Description
31-16
Reserved
R
0h
15
I2C_EN
R/W
0h
I2C module enable.
When this bit is cleared to 0, the I2C controller is not enabled and
reset.
When 0, receive and transmit FIFOs are cleared and all status bits
are set to their default values.
All configuration registers (I2C_IRQENABLE_SET,
I2C_IRQWAKE_SET, I2C_BUF, I2C_CNT, I2C_CON, I2C_OA,
I2C_SA, I2C_PSC, I2C_SCLL and I2C_SCLH) are not reset, they
keep their initial values and can be accessed.
The CPU must set this bit to 1 for normal operation.
Value after reset is low.
0x0 = Controller in reset. FIFO are cleared and status bits are set to
their default value.
0x1 = Module enabled
14
Reserved
R
0h
13-12
OPMODE
R/W
0h
Operation mode selection.
These two bits select module operation mode.
Value after reset is 00.
0x0 = I2C Fast/Standard mode
0x1 = Reserved
0x2 = Reserved
0x3 = Reserved
11
STB
R/W
0h
Start byte mode (I2C master mode only).
The start byte mode bit is set to 1 by the CPU to configure the I2C in
start byte mode (I2C_SA = 0000 0001).
See the Philips I2C spec for more details [1].
Value after reset is low.
0x0 = Normal mode
0x1 = Start byte mode
3749
SPRUH73H – October 2011 – Revised April 2013
I2C
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