Renesas H8S/2111B - Manual (Page 348)

Rev. 1.00, 05/04, page 314 of 544
13.4.4 Master Receive Operation
In I 2 C bus format master receive mode, the master device outputs the receive clock, receives data,
and returns an acknowledge signal. The slave device transmits data.
The master device transmits data containing the slave address and R/
W (1: read) in the first frame
following the start condition issuance in master transmit mode, selects the slave device, and then
switches the mode for receive operation.
Receive Operation Using the HNDS Function (HNDS = 1):
Figure 13.10 shows the sample flowchart for the operations in master receive mode (HNDS = 1).
End
Set TRS = 0 in ICCR
Set ACKB = 1 in ICSR
Read IRIC flag in ICCR
Clear IRIC flag in ICCR
Clear IRIC flag in ICCR
Clear IRIC flag in ICCR
Set HNDS = 1 in ICXR
Set BBSY = 0 and
SCP = 0 in ICCR
IRIC = 1?
No
Yes
Yes
Read ICDR
No
[4] Clear IRIC flag.
[1] Select receive mode.
[2] Start receiving. The first read is a dummy read.
[5] Read the receive data (for the second and subsequent read)
[3] Wait for 1 byte to be received.
(Set IRIC at the rise of the 9th clock for the receive frame)
[6] Set acknowledge data for the last reception.
[10] Read the receive data.
[9] Clear IRIC flag.
[7] Read the receive data.
Dummy read to start receiving if the first frame is
the last receive data.
[11] Set stop condition issuance.
Generate stop condition.
Master receive mode
Read IRIC flag in ICCR
IRIC = 1?
No
Yes
[8] Wait for 1 byte to be received.
Set ACKB = 0 in ICSR
Is next
receive the last one?
Last receive?
Read ICDR
Read ICDR
Set TRS = 1 in ICCR
Figure 13.10 Sample Flowchart for Operations in Master Receive Mode
(HNDS = 1)