R01UH0092EJ0110 Rev.1.10
Page 468 of 807
Jul 31, 2012
M16C/64C Group
23. Serial Interface UARTi (i = 0 to 2, 5 to 7)
23.2.10 UARTi Special Mode Register 3 (UiSMR3) (i = 0 to 2, 5 to 7)
NODC (Clock output select bit) (b3)
This function is used to set P-channel transistor of the CMOS output buffer always off, but not to
change the CLKi pin to open drain output completely.
Refer to the electrical characteristics for the input voltage range.
DL2-DL0 (SDAi digital delay setup bit) (b7-b5)
Bits DL2 to DL0 are used to generate a digital delay in SDAi output in I
2
C mode. Except in I
2
C mode,
set these bits to 000b (no delay).
The delay length varies with the load on pins SCLi and SDAi. Also, when using an external clock, the
delay length increases by about 100 ns.
b7 b6 b5 b4
b1
b2
b3
b0
Function
Bit Symbol
Bit Name
RW
DL1
RW
DL0
SDAi digital delay
setup bit
b7 b6 b5
0 0 0 : No delay
0 0 1 : 1 to 2 cycles of UiBRG count source
0 1 0 : 2 to 3 cycles of UiBRG count source
0 1 1 : 3 to 4 cycles of UiBRG count source
1 0 0 : 4 to 5 cycles of UiBRG count source
1 0 1 : 5 to 6 cycles of UiBRG count source
1 1 0 : 6 to 7 cycles of UiBRG count source
1 1 1 : 7 to 8 cycles of UiBRG count source
—
(b0)
—
No register bit. If necessary, set to 0. Read as undefined value
RW
CKPH
Clock phase set bit
0 : No clock delay
1 : With clock delay
—
(b2)
—
No register bit. If necessary, set to 0. Read as undefined value
RW
NODC
Clock output select bit
0 : CLKi is CMOS output
1 : CLKi is N-channel open drain output
DL2
RW
RW
—
(b4)
—
No register bit. If necessary, set to 0. Read as undefined value
UARTi Special Mode Register 3 (i = 0 to 2, 5 to 7)
Symbol
Address
Reset Value
U0SMR3, U1SMR3, U2SMR3
0245h, 0255h, 0265h
000X 0X0Xb
U5SMR3, U6SMR3, U7SMR3
0285h, 0295h, 02A5h
000X 0X0Xb
Содержание M16C Series
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