318
CHAPTER 17 SERIAL INTERFACE IIC0 (
µ
PD780344Y, 780354Y SUBSERIES ONLY)
User’s Manual U15798EJ2V0UD
Figure 17-5. Format of IIC Transfer Clock Select Register 0 (IICCL0) (2/2)
CL00
Selection of transfer rate
Standard mode
High-speed mode
CLX0 = 0
CLX0 = 1
0
f
X
/88 (95.2 kHz)
Note 1
f
X
/48 (175 kHz)
Note 3
f
X
/24 (350 kHz)
Note 4
1
f
X
/172 (48.7 kHz)
Note 2
Notes 1.
Transfer rate can only be used when f
X
= 4.0 to 8.38 MHz.
2.
Transfer rate can only be used when f
X
= 8.38 to 10 MHz.
3.
Transfer rate can only be used when f
X
= 8.0 to 10 MHz.
4.
Transfer rate can only be used when f
X
= 8.0 to 8.38 MHz.
Caution
Stop serial transfer once before rewriting CL00 to other than the same value.
Remarks 1.
CLX0: Bit 0 of IIC function expansion register 0 (IICX0)
2.
f
X
: Main system clock oscillation frequency
3.
Figures in parentheses are for operation with f
X
= 8.38 MHz.
(4) IIC function expansion register 0 (IICX0)
This register is used to set the function expansion for the I
2
C bus.
IICX0 is set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets IICX0 to 00H.
Figure 17-6. Format of IIC Function Expansion Register 0 (IICX0)
Address: FFA8H After reset: 00H R/W
Symbol
7
6
5
4
3
2
1
0
IICX0
0
0
0
0
0
0
0
CLX0
CLX0
Selection of transfer rate in high-speed mode
0
f
X
/48 (175 kHz)
Note 1
1
f
X
/24 (350 kHz)
Note 2
Notes 1.
Transfer rate can only be used when f
X
= 8.0 to 10 MHz.
2.
Transfer rate can only be used when f
X
= 8.0 to 8.38 MHz.
Cautions 1. This register is valid only in the high-speed mode. In the standard mode, this register is
invalid.
2. Stop serial transfer once before rewriting IICX0 to other than the same value.
Remarks 1.
f
X
: Main system clock oscillation frequency
2.
Figures in parentheses are for operation with f
X
= 8.38 MHz.
Содержание mPD780344 Series
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