Section 18
I
2
C Bus Interface (IIC)
Rev. 1.00 Mar. 12, 2008 Page 641 of 1178
REJ09B0403-0100
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. Initialize slave receive mode and wait for slave address reception.
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. 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 IRIC flag is set to 1 at the rise of the 9th clock. If the IEIC
bit in ICCR has been set to 1, an interrupt request is sent to the CPU. At the same time, the
ICDRE flag is set to 1. The slave device drives SCL low from the fall of the 9th transmit clock
until ICDR data is written, to disable the master device to output the next transfer clock.
3. After clearing the IRIC flag to 0, write data to ICDR. At this time, the ICDRE flag is cleared to
0. The written data is transferred to ICDRS, and the ICDRE and IRIC flags are set to 1 again.
The slave device sequentially sends the data written into ICDRS in accordance with the clock
output by the master device.
The IRIC flag is cleared to 0 to detect the end of transmission. Processing from the ICDR
register writing to the IRIC flag clearing should be performed continuously. Prevent any other
interrupt processing from being inserted.
4. 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 successfully. 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. When the ICDRE flag is 0, the data written into ICDR is transferred to ICDRS and the
ICDRE and IRIC flags are set to 1 again. If the ICDRE flag has been set to 1, this slave device
drives SCL low from the fall of the 9th transmit clock until data is written to ICDR.
5. To continue transmission, write the next data to be transmitted into ICDR. The ICDRE flag is
cleared to 0. The IRIC flag is cleared to 0 to detect the end of transmission. Processing from
the ICDR register writing to the IRIC flag clearing should be performed continuously. Prevent
any other interrupt processing from being inserted.
Transmit operations can be performed continuously by repeating steps 4 and 5.
6. Clear the IRIC flag to 0.
7. To end transmission, clear the ACKE bit in the ICCR register to 0, to clear the acknowledge
bit stored in the ACKB bit to 0.
8. Clear the TRS bit to 0 for the next address reception, to set slave receive mode.
9. Dummy-read ICDR to release SCL on the slave side.
Содержание H8S Family
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Страница 152: ...Section 5 Interrupt Controller Rev 1 00 Mar 12 2008 Page 104 of 1178 REJ09B0403 0100...
Страница 206: ...Section 6 Bus Controller BSC Rev 1 00 Mar 12 2008 Page 158 of 1178 REJ09B0403 0100...
Страница 420: ...Section 9 14 Bit PWM Timer PWMX Rev 1 00 Mar 12 2008 Page 372 of 1178 REJ09B0403 0100...
Страница 476: ...Section 12 Watchdog Timer WDT Rev 1 00 Mar 12 2008 Page 428 of 1178 REJ09B0403 0100...
Страница 552: ...Section 14 CRC Operation Circuit CRC Rev 1 00 Mar 12 2008 Page 504 of 1178 REJ09B0403 0100...
Страница 588: ...Section 15 Serial Communication Interface with FIFO SCIF Rev 1 00 Mar 12 2008 Page 540 of 1178 REJ09B0403 0100...
Страница 632: ...Section 17 Synchronous Serial Communication Unit SSU Rev 1 00 Mar 12 2008 Page 584 of 1178 REJ09B0403 0100...
Страница 712: ...Section 18 I2 C Bus Interface IIC Rev 1 00 Mar 12 2008 Page 664 of 1178 REJ09B0403 0100...
Страница 804: ...Section 19 LPC Interface LPC Rev 1 00 Mar 12 2008 Page 756 of 1178 REJ09B0403 0100...
Страница 838: ...Section 20 Ethernet Controller EtherC Rev 1 00 Mar 12 2008 Page 790 of 1178 REJ09B0403 0100...
Страница 964: ...Section 24 RAM Rev 1 00 Mar 12 2008 Page 916 of 1178 REJ09B0403 0100...
Страница 1066: ...Section 25 Flash Memory Rev 1 00 Mar 12 2008 Page 1018 of 1178 REJ09B0403 0100...
Страница 1098: ...Section 26 Boundary Scan JTAG Rev 1 00 Mar 12 2008 Page 1050 of 1178 REJ09B0403 0100...
Страница 1168: ...Section 30 Platform Environment Control Interface PECI Rev 1 00 Mar 12 2008 Page 1120 of 1178 REJ09B0403 0100...
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Страница 1230: ...H8S 2472 Group H8S 2462 Group Hardware Manual...