HD64F2636F20 Datasheet, PDF (635/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
Section 15 I²C Bus Interface [Option]
(Only for the H8S/2638, H8S/2639, and H8S/2630)
[1] Clear the TRS bit in ICCR to 0 to switch from transmit mode to receive mode. Clear the
ACKB bit in ICSR to 0 (acknowledge data setting). Clear the IRIC flag to 0, then set the
WAIT bit in ICMR to 1.
[2] When ICDR is read (dummy data read), reception is started, and the receive clock is output,
and data received, in synchronization with the internal clock.
[3] The IRIC flag is set to 1 by the following two conditions. At that point, an interrupt request is
issued to the CPU if the IEIC bit in ICCR is set to 1.
1. The flag is set at the falling edge of the 8th clock cycle of the receive clock for 1 frame.
SCL is automatically held low, in synchronization with the internal clock, until the IRIC
flag is cleared.
2. The flag is set at the rising edge of the 9th clock cycle of the receive clock for 1 frame.
The IRIC flag and ICDRF flag are set to 1, indicating that reception of 1 frame of data has
ended. The master device continues to output the receive clock for the receive data.
[4] Read the IRTR flag in ICSR. If the IRTR flag value is 0, the wait state is cancelled by
clearing the IRIC flag as described in step [6] below. If the IRTR flag value is 1 and the next
receive data is the final receive data, perform the end processing described in step [7] below.
[5] If the IRTR flag value is 1, read the ICDR receive data.
[6] Clear the IRTR flag to 0. If condition [3]-1 is true, the master device drives SDA to low level
and returns an acknowledge signal when the receive clock outputs the 9th clock cycle.
Further data can be received by repeating steps [3] through [6].
[7] Set the ACKB bit in ICSR to 1 to set the acknowledge data for the final receive.
[8] Wait for at least 1 clock cycle after the IRIC flag is set to 1 and then wait for the rising edge
of the 1st clock cycle of the next receive data.
[9] Set the TSR bit in ICCR to 1 to switch from the receive mode to the transmit mode. The TSR
bit setting value at this point becomes valid when the rising edge of the next 9th clock cycle
is input.
[10] Read the ICDR receive data.
[11] Clear the IRTR flag to 0.
[12] The IRIC flag is set to 1 by the following two conditions.
1. The flag is set at the falling edge of the 8th clock cycle of the receive clock for 1 frame.
SCL is automatically held low, in synchronization with the internal clock, until the IRIC
flag is cleared.
2. The flag is set at the rising edge of the 9th clock cycle of the receive clock for 1 frame.
The IRIC flag and ICDRF flag are set to 1, indicating that reception of 1 frame of data has
ended. The master device continues to output the receive clock for the receive data.
[13] Read the IRTR flag in ICSR. If the IRTR flag value is 0, the wait state is cancelled by
clearing the IRIC flag as described in step [14] below. If the IRTR flag value is 1 and the
REJ09B0103-0800 Rev. 8.00
May 28, 2010
Page 585 of 1458