H836087 Datasheet, PDF (353/506 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER R8C FAMILY / R8C/1x SERIES

Section 17 I²C Bus Interface 2 (IIC2)
17.3.7 I²C Bus Transmit Data Register (ICDRT)
ICDRT is an 8-bit readable/writable register that stores the transmit data. When ICDRT detects the
space in the shift register (ICDRS), it transfers the transmit data which is written in ICDRT to
ICDRS and starts transferring data. If the next transfer data is written to ICDRT during
transferring data of ICDRS, continuous transfer is possible. If the MLS bit of ICMR is set to 1
and when the data is written to ICDRT, the MSB/LSB inverted data is read. The initial value of
ICDRT is H'FF.
17.3.8 I²C Bus Receive Data Register (ICDRR)
ICDRR is an 8-bit register that stores the receive data. When data of one byte is received, ICDRR
transfers the receive data from ICDRS to ICDRR and the next data can be received. ICDRR is a
receive-only register, therefore the CPU cannot write to this register. The initial value of ICDRR
is H'FF.
17.3.9 I²C Bus Shift Register (ICDRS)
ICDRS is a register that is used to transfer/receive data. In transmission, data is transferred from
ICDRT to ICDRS and the data is sent from the SDA pin. In reception, data is transferred from
ICDRS to ICDRR after data of one byte is received. This register cannot be read directly from the
CPU.
Rev. 2.00 Sep. 23, 2005 Page 323 of 472
REJ09B0160-0200