Renesas g1a Answering Machine User Manual


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RL78/G1A CHAPTER 13 SERIAL INTERFACE IICA
An example of the processing procedure of the slave with the INTIICA0 interrupt is explained below (processing is
performed assuming that no extension code is used). The INTIICA0 interrupt checks the status, and the following
operations are performed.
<1> Communication is stopped if the stop condition is issued.
<2> If the start condition is issued, the address is checked and communication is completed if the address does
not match. If the address matches, the communication mode is set, wait is cancelled, and processing returns
from the interrupt (the ready flag is cleared).
<3> For data transmit/receive, only the ready flag is set. Processing returns from the interrupt with the I
2
C bus
remaining in the wait state.
Remark <1> to <3> above correspond to <1> to <3> in Figure 13-31 Slave Operation Flowchart (2).
Figure 13-31. Slave Operation Flowchart (2)
Yes
Yes
Yes
No
No
No
INTIICA0 generated
Set ready flag
Interrupt servicing completed
SPD0 = 1?
STD0 = 1?
COI0 = 1?
Communication direction flag
TRC0
Set communication mode flag
Clear ready flag
Clear communication direction
flag, ready flag, and
communication mode flag
<1>
<2>
<3>
13.5.17 Timing of I
2
C interrupt request (INTIICA0) occurrence
The timing of transmitting or receiving data and generation of interrupt request signal INTIICA0, and the value of the
IICA status register 0 (IICS0) when the INTIICA0 signal is generated are shown below.
Remark ST: Start condition
AD6 to AD0: Address
R/W: Transfer direction specification
ACK: Acknowledge
D7 to D0: Data
SP: Stop condition
R01UH0305EJ0200 Rev.2.00 616
Jul 04, 2013