RL78/G1P
CHAPTER 12 SERIAL INTERFACE IICA
R01UH0895EJ0100 Rev.1.00
486
Nov 29, 2019
Caution Note the minimum f
CLK
operation frequency when setting the transfer clock. The minimum f
CLK
operation frequency for serial interface IICA is determined according to the mode.
Fast mode:
f
CLK
= 3.5 MHz (MIN.)
Fast mode plus: f
CLK
= 10 MHz (MIN.)
Normal
mode:
f
CLK
= 1 MHz (MIN.)
In addition, the fastest operation frequency of the operation clock of the serial interface IICA is 20
MHz (Max.). If the f
CLK
exceeds 20 MHz, set the clock to f
CLK
/2 by setting the PRSn bit of IICCTLn1
register to 1.
Remarks 1.
Calculate the rise time (t
R
) and fall time (t
F
) of the SDAAn and SCLAn signals separately, because
they differ depending on the pull-up resistance and wire load.
2.
IICWLn:
IICA
low-level
width setting register n
IICWHn:
IICA
high-level
width setting register n
t
F
:
SDAAn and SCLAn signal falling times
t
R
:
SDAAn and SCLAn signal rising times
f
CLK
:
CPU/peripheral hardware clock frequency
3.
n = 0, 1