I2C Registers
Table 21-33. I2C_SYSTEST Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
8
SCL_I_FUNC
R
0h
SCL line input value (functional mode).
This read-only bit returns the logical state taken by the SCL line
(either 1 or 0).
It is active both in functional and test mode.
Value after reset is low.
0x0 = Read 0 from SCL line
0x1 = Read 1 from SCL line
7
SCL_O_FUNC
R
0h
SCL line output value (functional mode).
This read-only bit returns the value driven by the module on the SCL
line (either 1 or 0).
It is active both in functional and test mode.
Value after reset is low.
0x0 = Driven 0 on SCL line
0x1 = Driven 1 on SCL line
6
SDA_I_FUNC
R
0h
SDA line input value (functional mode).
This read-only bit returns the logical state taken by the SDA line
(either 1 or 0).
It is active both in functional and test mode.
Value after reset is low.
0x0 = Read 0 from SDA line
0x1 = Read 1 from SDA line
5
SDA_O_FUNC
R
0h
SDA line output value (functional mode).
This read-only bit returns the value driven by the module on the SDA
line (either 1 or 0).
It is active both in functional and test mode.
Value after reset is low.
0x0 = Driven 0 to SDA line
0x1 = Driven 1 to SDA line
4
Reserved
R
0h
3
SCL_I
R
0h
SCL line sense input value.
In normal functional mode (ST_EN = 0), this read-only bit always
reads 0.
In system test mode (ST_EN = 1 and TMODE = 11), this read-only
bit returns the logical state taken by the SCL line (either 1 or 0).
Value after reset is low.
0x0 = Read 0 from SCL line
0x1 = Read 1 from SCL line
2
SCL_O
R
0h
SCL line drive output value.
In normal functional mode (ST_EN = 0), this bit is don't care.
It always reads 0 and a write is ignored.
In system test mode (ST_EN = 1 and TMODE = 11), a 0 forces a
low level on the SCL line and a 1 puts the I2C output driver to a
high-impedance state.
Value after reset is low.
0x0 = Forces 0 on the SCL data line
0x1 = SCL output driver in high-impedance state
1
SDA_I
R
0h
SDA line sense input value.
In normal functional mode (ST_EN = 0), this read-only bit always
reads 0.
In system test mode (ST_EN = 1 and TMODE = 11), this read-only
bit returns the logical state taken by the SDA line (either 1 or 0).
Value after reset is low.
0x0 = Read 0 from SDA line
0x1 = Read 1 from SDA line
3759
SPRUH73H – October 2011 – Revised April 2013
I2C
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