Renesas H8S/2111B, Hardware Manual

Page: 370 / 582

Rev. 1.00, 05/04, page 336 of 544
The value of the BBSY bit cannot be modified directly by this module clear function, but since the
stop condition pin waveform is generated according to the state and release timing of the SCL and
SDA pins, the BBSY bit may be cleared as a result. Similarly, state switching of other bits and
flags may also have an effect.
To prevent problems caused by these factors, the following procedure should be used when
initializing the IIC state.
1. Execute initialization of the internal state according to the setting of bits CLR3 to CLR0 or
ICE bit clearing.
2. Execute a stop condition issuance instruction (write 0 to BBSY and SCP) to clear the BBSY
bit to 0, and wait for two transfer rate clock cycles.
3. Re-execute initialization of the internal state according to the setting of bits CLR3 to CLR0 or
ICE bit clearing.
4. Initialize (re-set) the IIC registers.
13.5 Interrupt Sources
The IIC has interrupt source IICI. Table 13.7 shows the interrupt sources and priority. Individual
interrupt sources can be enabled or disabled using the enable bits in ICCR, and are sent to the
interrupt controller independently.
Table 13.7 IIC Interrupt Sources
Channel Name Enable Bit Interrupt Source Interrupt Flag Priority
0 IICI0 IEIC I
2
C bus interface
interrupt request
IRIC High
1 IICI1 IEIC I
2
C bus interface
interrupt request
IRIC
Low