Renesas M16C/64A Series User Manual page 642

M16C/64A Group
26.3.6.2 Arbitration Lost Detection
When data is transmitted, an arbitration lost is detected in the following cases:
•
The CEC output changes from Hi-Z to low by the external source.
•
When changing the CEC pin from low output to Hi-Z, the pin level remains low even though it is
outside the tolerated range.
A range for detecting the arbitration lost is selected by the CTABTS bit in the CECC2 register. Figure
26.14 shows Arbitration Lost Detectable Range.
When the arbitration lost is detected, the CTABTFLG bit in the CECFLG register becomes 1 (arbitra-
tion lost detected).
CEC
ST
The detectable range when the CTABTS bit is set to 0
The detectable range when the CTABTS bit is set to 1
CTABTS bit: Bit in the CECC2 register
Figure 26.14 Arbitration Lost Detectable Range
26.3.6.3 Transmission Example
Figure 26.15 shows a Transmission Example, Figure 26.16 shows a Transmission Example (When
NACK Received) and Figure 26.17 shows a Transmission Example (When an Arbitration Lost
Detected).
Set the CTXDEN bit in the CECC3 register to 0 (transmit disabled) after the transmission. To continue
the transmission, set the CTXDEN bit to 0 (transmit disabled) after sending one frame (one header
block and one or more data blocks), and wait for one or more cycles of the count source before setting
the CTXDEN bit to 1 (transmit enabled).
R01UH0136EJ0210 Rev.2.10
Jul 31, 2012
Initiator address Destination address
H7 H6 H5 H4 H3
26. Consumer Electronics Control (CEC) Function
H2 H1 H0 EOM ACK D7 D0 ACK
EOM
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