Inter-Integrated Circuit Controller
7-86
Values after reset are low (2 bits).
In SCL counter test mode, the SCL pin is driven with a permanent clock as
if master with the parameters set in I2C_PSC, I2C_SCLL, and I2C_SCLH
registers.
Loopback mode: In the master transmit mode only, data transmitted out of the
I2C_DATA register (write action) is received in the same I2C_DATA register
via an internal path through the 1-deep FIFO buffers. The DMA and interrupt
requests is normally generated if enabled.
In SDA/SCL I/O mode, the SCL IO and SDA IO are controlled via the
I2C_SYSTEST[3:0] register bits.
SCL Line Sense Input Value (SCL_I)
In normal functional mode (ST_EN = 0), this read-only bit (3) always reads
as 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.
SCL Line Drive Output Value (SCL_O)
In normal functional mode (ST_EN = 0), this bit (2) is don’t care, and always
reads as 0. Writes are 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 I
2
C output driver in a high-impedance state.
-
0: Force 0 on the SCL data line
-
1: SCL output driver in HI-Z state
Value after reset is low.
SDA Line Sense Input Value (SDA_I)
In normal functional mode (ST_EN = 0), this read-only-bit (1) always reads
as 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.