Renesas R8C/20 User Manual

R8C/20 Group, R8C/21 Group 16. Clock Synchronous Serial Interface
Rev.2.00 Aug 27, 2008 Page 317 of 458
REJ09B0250-0200
Figure 16.26 ICMR Register
IIC Bus Mode Register
Symbol Address After Reset
ICMR 00BAh 00011000b
Bit Symbol Bit Name Function RW
MSB-first / LSB-first select
NOTES:
1.
2.
3.
4.
5.
6. Set to 0 w hen the I
2
C bus format is used.
When w rite to the BC0 to BC2 bits, w rite 0 to the BCWP bit usin
g
the MOV instruction.
—
(b4)
Nothing is assigned. If necessary, set to 0.
When read, the content is 1.
—
Rew rite betw een transfer frames. When w rite values other than 000b, w rite w hen the SCL si
g
nal is “L”.
After data including the acknowledge bit is transferred, bits b2 to b0 are automatically set to 000b. When the start
condition is detected, these bits are automatically set to 000b.
Do not rew rite w hen the clock s
y
nchronous serial format is used.
Reserved bit
When rew rite to the BC0 to BC2 bits, w rite 0
simultaneously.
(2,4)
When read, its content is 1.
RW
The setting value is enabled in master mode of the I
2
C bus format. It is disabled in slave mode of the I
2
C bus format or
w hen the clock synchronous serial format is used.
0 : No w ait
(Transfer data and acknow ledge bit
consecutively)
1 : Wait
(After the falling of the clock for the final
data bit, “L” period is extended for tw o
transfer clocks)
Set to 0
RW
RW
0 : Data transfer by MSB-first
(6)
1 : Data transfer by LSB-first
—
(b5)
WAIT
b3 b2 b1 b0b7 b6 b5 b4
Wait insertion bit
(5)
BCWP
BC w rite protect bit
RW
0
MLS RW
RW
BC1
BC2
Bit counter 2 to 0 I
2
C bus format (remaining transfer bit numbers
w hen read out and data bit numbers of transfer to
the next w hen w rite)
(1,2)
b2 b1 b0
0 0 0 : 9 bits
(3)
0 0 1 : 2 bits
0 1 0 : 3 bits
0 1 1 : 4 bits
1 0 0 : 5 bits
1 0 1 : 6 bits
1 1 0 : 7 bits
1 1 1 : 8 bits
Clock synchronous serial format (w hen read, read
the remaining transfer bit numbers and w hen w rite,
w rite 000b.)
b2 b1 b0
0 0 0 : 8 bits
0 0 1 : 1 bit
0 1 0 : 2 bits
0 1 1 : 3 bits
1 0 0 : 4 bits
1 0 1 : 5 bits
1 1 0 : 6 bits
1 1 1 : 7 bits
BC0
RW

Renesas R8C/20 Specifications

General

Brand	Renesas
Model	R8C/20
Category	Control Unit
Language	English