0X4344: I 2 C Data Register (I2C_Dat) - Epson S1C17001 Technical Manual

2
0x4344: I C Data Register (I2C_DAT)
Register name Address Bit
I 2 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): Receive data exists
0 (R): No receive data (default)
The RBRDY flag becomes 1 when the data received in the shift register is loaded to RTDT[7:0] (D[7:0])
and reverts to 0 when the receive data is read out from RTDT[7:0]. Interrupts can also be generated
once the flag value becomes 1, so either use this interrupt or read the receive data to determine the pres-
ence of valid receive data in RTDT[7:0] by inspecting the RBRDY flag before reading out the receive
data.
D10 RXE: Receive Execution Bit
Receives 1 byte of data.
1 (R/W): Data receipt start
0 (R/W): Disabled (default)
Setting RXE to 1 and TXE (D9) to 0 starts receiving for 1 byte of data. RXE can be set to 1 for subse-
quent receipt, even if the slave address is being sent or data is being received. RXE is reset to 0 as soon
as D6 is loaded to the shift register.
D9 TXE: Transmit Execution Bit
Transmits 1 byte of data.
1 (R/W): Data transmission start
0 (R/W): Disabled (default)
Transmission is started by setting the transmission data to RTDT[7:0] (D[7:0]) and writing 1 to TXE.
TXE can be set to 1 for subsequent transmission, even if the slave address or data is being sent. TXE is
reset to 0 as soon as the data set in RTDT[7:0] is transferred to the shift register.
D8 RTACK: Receive/Transmit ACK Bit
When transmitting data
Indicates the response bit status.
1 (R/W): Error (NACK)
0 (R/W): ACK (default)
RTACK becomes 0 when ACK is returned from the slave after 1 byte of data is sent, indicating that the
slave has received the data correctly. If RTACK is 1, the slave device is not operating or the data was
not received correctly.
When receiving data
Sets the response bit sent to the slave.
1 (R/W): Error (NACK)
0 (R/W): ACK (default)
To return an ACK after data has been received, RTACK should be set to 0 before the I
the response bit.
To return an NACK, set RTACK to 1.
S1C17001 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
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