0X4344: I 2 C Data Register (I2C_Dat) - Epson S1C17704 Technical Manual

2
0x4344: I C Data Register (I2C_DAT)
Register name Address Bit
2
I C Data 0x4344 D15–12 –
Register (16 bits)
D11
(I2C_DAT)
D10
D9
D8
D7–0 RTDT[7:0]
D[15:12] Reserved
D11 RBRDY: Receive Buffer Ready Flag
Indicates the receive buffer status.
1 (R): Received data is present
0 (R): No received data is present (default)
The RBRDY flag goes 1 when the received data in the shift register is loaded into RTDT[7:0] (D[7:0])
and returns to 0 when the received data is read from RTDT[7:0]. An interrupt can be generated when
this flag goes 1. Use this interrupt or read the RBRDY flag to check that RTDT[7:0] contains valid data
when reading received data.
D10 RXE: Receive Execution Bit
Execute a data reception for one byte.
1 (R/W): Start data reception
0 (R/W): Ignore (default)
2
The I C module starts data reception for one byte by setting RXE to 1 and TXE (D9) to 0. RXE can be
set to 1 for the next data reception even if a slave address is being transmitted or data is being received.
RXE is reset to 0 when D6 is input to the shift register.
D9 TXE: Transmit Execution Bit
Execute a data transmission for one byte.
1 (R/W): Start data transmission
0 (R/W): Ignore (default)
Set the transmit data to RTDT[7:0] (D[7:0]) and write 1 to TXE to start data transmission. TXE can be
set to 1 for the next data transmission even if a slave address or data is being transmitted. TXE is reset
to 0 when the data set in RTDT[7:0] is transferred to the shift register.
D8 RTACK: Receive/Transmit ACK Bit
In data transmission
Indicates the acknowledge bit status.
1 (R/W): Error (NACK)
0 (R/W): ACK (default)
This bit is set to 0 when the slave returned ACK after one-byte data has been transmitted. This indicates
that the slave could receive the data normally. If this bit is set to 1, the slave may be inactive or it could
not receive the data normally.
In data reception
Set the acknowledge bit to be sent to the slave.
1 (R/W): Error (NACK)
0 (R/W): ACK (default)
To return ACK to the slave after data is received, set RTACK to 0 before the I
acknowledge bit.
To return NACK, set RTACK to 1.
S1C17704 TECHNICAL MANUAL
Name Function
reserved
RBRDY Receive buffer ready
RXE Receive execution
TXE Transmit execution
RTACK
Receive/transmit ACK
Receive/transmit data
RTDT7 = MSB
RTDT0 = LSB
EPSON
Setting Init. R/W
–
1 Ready 0 Empty
1 Receive 0 Ignored
1 Transmit 0 Ignored
1 Error 0 ACK
0x0 to 0xff 0x0 R/W
2
20 I C
Remarks
– – 0 when being read.
0 R
0 R/W
0 R/W
0 R/W
2
C module sends the
20-17