
20 I2C Master (I2CM)
S1C17003 TECHNICAL MANUAL
EPSON
20-13
I2CM
0x4342: I2C Control Register (I2C_CTL)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
I2C Control
Register
(I2C_CTL)
0x4342
(16 bits)
D15–10
–
reserved
–
0 when being read.
D9
RBUSY
Receive busy flag
1 Busy
0 Idle
0
R
D8
TBUSY
Transmit busy flag
1 Busy
0 Idle
0
R
D7–5
–
reserved
–
0 when being read.
D4
NSERM
Noise remove on/off
1 On
0 Off
0
R/W
D3–2
–
reserved
–
0 when being read.
D1
STP
Stop control
1 Stop
0 Ignored
0
R/W
D0
STRT
Start control
1 Start
0 Ignored
0
R/W
D[15:10] Reserved
D9
RBUSY: Receive Busy Flag
Indicates I2C master module receive operation status.
1 (R):
Busy
0 (R):
Idle (Default)
The RBUSY bit is set to 1 when I2C master module has started data reception, and the value is retained
during the reception. When the receive process has been completed, the RBUSY bit is cleared to 0.
D8
TBUSY: Transmit Busy Flag
Indicates I2C master transmit operation status.
1 (R):
Busy
0 (R):
Idle (Default)
The RBUSY bit is set to 1 when I2C master module has started data transmissin, and the value is
retained during the transmission. When the transmit process has been completed, the RBUSY bit is
cleared to 0.
D[7:5]
Reserved
D4
NSERM: Noise Remove On/Off Bit
Turns the noise filter function on or off.
1 (R/W): On
0 (R/W): Off (default)
The I2C master module incorporates a function for filtering noise from the SDA0 and SCL0 pin input
signals. This function is enabled by setting NSERM to 1.
Note that using this function requires setting the I2C master clock (16-bit timer Ch.2 output clock)
frequency to 1/6 or less of PCLK.
D[3:2]
Reserved
D1
STP: Stop Control Bit
Generates the stop condition.
1 (R/W): Stop condition generated
0 (R/W): Disabled (default)
Setting the STP bit 1 makes the I2C master module generate the stop condition by switching the SDA
line from Low to High while keeping the I2CM bus SCL line in High state. The I2C bus is in free status
in the subsequent processes.
The generation of the stop condition is programmable. To program the stop condition, check that I2C
master module is operating (TBUSY(D8)=1 or RBUSY(D9)=1), and then set the STP bit to 1. The stop
condition is generated once the data transfer (including ACK transfer) has been completed.
The generation of the stop condition automatically resets the STP bit to 0.