Renesas R8C series User Manual

R8C/1A Group, R8C/1B Group 20. Usage Notes
Rev.1.30 Dec 08, 2006 Page 304 of 315
REJ09B0252-0130
20.5.2 Notes on I
2
C bus Interface
Set the IICSEL bit in the PMR register to 1 (select I
2
C bus interface function) to use the I
2
C bus interface.
20.5.2.1 Accessing of Registers Associated with I
2
C bus Interface
Wait for three instructions or more or four cycles or more after writing to the same register among the registers
associated with the I
2
C bus Interface (00B8h to 00BFh) before reading it.
• An example of waiting three instructions or more
Program example MOV.B #00h,00BBh ; Set ICIER register to 00h
NOP
NOP
NOP
MOV.B 00BBh,R0L
• An example of waiting four cycles or more
Program example BCLR 6,00BBh ; Disable transmit end interrupt request
JMP.B NEXT
NEXT:
BSET 7,00BBh ; Enable transmit data empty interrupt request

Renesas R8C series Specifications

General

Brand	Renesas
Model	R8C series
Category	Computer Hardware
Language	English