Datasheet

78K0/Kx2-L CHAPTER 15 SERIAL INTERFACE IICA
R01UH0028EJ0400 Rev.4.00 487
Sep 27, 2010
CHAPTER 15 SERIAL INTERFACE IICA
15.1 Functions of Serial Interface IICA
Serial interface IICA is mounted onto all 78K0/Kx2-L microcontroller products.
Serial interface IICA has the following three modes.
(1) Operation stop mode
This mode is used when serial transfers are not performed. It can therefore be used to reduce power consumption.
(2) I
2
C bus mode (multimaster supported)
This mode is used for 8-bit data transfers with several devices via two lines: a serial clock (SCLA0) line and a serial
data bus (SDAA0) line.
This mode complies with the I
2
C bus format and the master device can generated “start condition”, “address”,
“transfer direction specification”, “data”, and “stop condition” data to the slave device, via the serial data bus. The
slave device automatically detects these received status and data by hardware. This function can simplify the part
of application program that controls the I
2
C bus.
Since the SCLA0 and SDAA0 pins are used for open drain outputs, serial interface IICA requires pull-up resistors
for the serial clock line and the serial data bus line.
(3) Wakeup mode
The STOP mode can be released by generating an interrupt request signal (INTIICA0) when an extension code
from the master device or a local address has been received while in STOP mode. This can be set by using the
WUP bit of the IICA control register 1 (IICACTL1).
Figure 15-1 shows a block diagram of serial interface IICA.