R01UH0092EJ0110 Rev.1.10
Page 588 of 807
Jul 31, 2012
M16C/64C Group
26. Consumer Electronics Control (CEC) Function
26.2.3
CEC Function Control Register 3 (CECC3)
CTXDEN (Transmit enable bit) (b0)
CRXDEN (Receive enable bit) (b1)
When changing the values of these bits, transmission/reception is enabled or disabled after one or
more cycles of the clock source elapses.
When setting the CTXDEN bit to 0 while transmitting/receiving, transmitting is disabled after ACK
completion. In the same way, when setting the CRXDEN bit to 0 while transmitting/receiving, reception
is disabled after ACK completion.
CREGCLR (Receive edge detect flag clear bit) (b2)
The CREGFLG bit in the CECC4 register becomes 0 by setting the CREGCLR bit to 1 when CEC input
is Hi-Z.
The CREGCLR bit retains the value written to it. In order set the CREGFLG bit to 0 again by setting the
CREGCLR bit to 1, first set the CREGCLR bit to 0, then set it to 1.
When setting the CREGCLR bit to 1 while CEC input is low, the CREGFLG bit becomes 0. If the
CREGCLR bit is set to 0 after that, the CREGFLG bit becomes 1.
Figure 26.2 shows the Operation of Bits CREGFLG and CREGCLR.
Figure 26.2
Operation of Bits CREGFLG and CREGCLR
Symbol
CECC3
Address
0352h
Reset Value
XXXX 0000b
CEC Function Control Register 3
Bit Symbol
Bit Name
Function
RW
CTXDEN
Transmit enable bit
0: Disabled
1: Enabled
RW
b7 b6 b5 b4 b3
b2 b1 b0
CRXDEN
Receive enable bit
0: Disabled
1: Enabled
RW
CREGCLR
Receive edge detect flag
clear bit
RW
CEOMI
RW
—
(b7-b4)
No register bits. If necessary, set to 0. Read as undefined value
—
The CREGFLG bit in the CECC4
register becomes 0 by setting 1 to
this bit
EOM disable bit
0: EOM enabled
1: EOM disabled (EOM ignored)
CEC
CREGCLR: Bit in the CECC3 register
CREGFLG: Bit in the CECC4 register
CREGFLG bit
CREGCLR bit
Becomes 1 when CEC
is low.
The CREGFLG bit
becomes 0 by setting
the CREGCLR bit to 0
when CEC is high.
When CEC is low, the
CREGFLG bit is 0
while the CREGCLR
bit is 1.
Summary of Contents for M16C Series
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