Section 17 I
2
C Bus Interface (IIC)
Rev. 3.00 Jan 25, 2006 page 525 of 872
REJ09B0286-0300
17.5.5
Slave Transmit Operation
In slave transmit mode, the slave device outputs the transmit data, while the master device outputs
the receive clock and returns an acknowledge signal. The transmission procedure and operations in
slave transmit mode are described below.
1. Set the ICE bit in ICCR to 1. Set the MLS bit in ICMR and the MST and TRS bits in ICCR
according to the operating mode.
2. When the slave address matches in the first frame following detection of the start condition,
the slave device drives SDA low at the 9th clock pulse and returns an acknowledge signal. At
the same time, the IRIC flag in ICCR is set to 1. If the IEIC bit in ICCR has been set to 1, an
interrupt request is sent to the CPU. If the 8th data bit (R/
W
) is 1, the TRS bit in ICCR is set to
1, and the mode changes to slave transmit mode automatically. The TDRE internal flag is set
to 1. The slave device drives SCL low from the fall of the transmit clock until ICDR data is
written.
3. After clearing the IRIC flag to 0, write data to ICDR. The TDRE internal flag is cleared to 0.
The written data is transferred to ICDRS, and the TDRE internal flag and IRIC and IRTR flags
are set to 1 again. After clearing the IRIC flag to 0, write the next data to ICDR. The slave
device sequentially sends the data written into ICDR in accordance with the clock output by
the master device at the timing shown in figure 17.12.
4. When one frame of data has been transmitted, the IRIC flag in ICCR is set to 1 at the rise of
the 9th transmit clock pulse. If the TDRE internal flag has been set to 1, this slave device
drives SCL low from the fall of the transmit clock until data is written to ICDR. The master
device drives SDA low at the 9th clock pulse, and returns an acknowledge signal. As this
acknowledge signal is stored in the ACKB bit in ICSR, this bit can be used to determine
whether the transfer operation was performed normally. When the TDRE internal flag is 0, the
data written into ICDR is transferred to ICDRS and the TDRE internal flag and IRIC and
IRTR flags are set to 1 again.
5. To continue transmission, clear the IRIC flag to 0, then write the next data to be transmitted
into ICDR. The TDRE internal flag is cleared to 0.
Transmit operations can be performed continuously by repeating steps [4] and [5]. To end
transmission, write H'FF to ICDR. When SDA is changed from low to high when SCL is high and
the stop condition is detected, the BBSY flag in ICCR is cleared to 0.
Summary of Contents for H8S/2158
Page 10: ...Rev 3 00 Jan 25 2006 page viii of lii...
Page 36: ...Rev 3 00 Jan 25 2006 page xxxiv of lii B Product Lineup 863 C Package Dimensions 864 Index 865...
Page 47: ...Rev 3 00 Jan 25 2006 page xlv of lii Appendix Figure C 1 Package Dimensions TBP 112A 864...
Page 54: ...Rev 3 00 Jan 25 2006 page lii of lii...
Page 70: ...Section 1 Overview Rev 3 00 Jan 25 2006 page 16 of 872 REJ09B0286 0300...
Page 118: ...Section 3 MCU Operating Modes Rev 3 00 Jan 25 2006 page 64 of 872 REJ09B0286 0300...
Page 126: ...Section 4 Exception Handling Rev 3 00 Jan 25 2006 page 72 of 872 REJ09B0286 0300...
Page 198: ...Section 6 Bus Controller Rev 3 00 Jan 25 2006 page 144 of 872 REJ09B0286 0300...
Page 326: ...Section 10 8 Bit PWM Timer PWM Rev 3 00 Jan 25 2006 page 272 of 872 REJ09B0286 0300...
Page 440: ...Section 15 Watchdog Timer WDT Rev 3 00 Jan 25 2006 page 386 of 872 REJ09B0286 0300...
Page 606: ...Section 17 I 2 C Bus Interface IIC Rev 3 00 Jan 25 2006 page 552 of 872 REJ09B0286 0300...
Page 742: ...Section 19 Multimedia Card Interface MCIF Rev 3 00 Jan 25 2006 page 688 of 872 REJ09B0286 0300...
Page 750: ...Section 21 D A Converter Rev 3 00 Jan 25 2006 page 696 of 872 REJ09B0286 0300...
Page 768: ...Section 22 A D Converter Rev 3 00 Jan 25 2006 page 714 of 872 REJ09B0286 0300...
Page 770: ...Section 23 RAM Rev 3 00 Jan 25 2006 page 716 of 872 REJ09B0286 0300...
Page 824: ...Section 26 Clock Pulse Generator Rev 3 00 Jan 25 2006 page 770 of 872 REJ09B0286 0300...
Page 844: ...Section 27 Power Down Modes Rev 3 00 Jan 25 2006 page 790 of 872 REJ09B0286 0300...
Page 878: ...Section 28 List of Registers Rev 3 00 Jan 25 2006 page 824 of 872 REJ09B0286 0300...
Page 926: ...Index Rev 3 00 Jan 25 2006 page 872 of 872 REJ09B0286 0300...