
APPENDIX B LIST OF CAUTIONS
User’s Manual U18432EJ5V0UD
932
(20/35)
Chapter
Cl
assi
fi
cati
on
Function
Details of
Function
Cautions
Page
The MDmn0 bit can be rewritten even during operation.
However, rewrite it before transfer of the last bit is started, so that it has been
rewritten before the transfer end interrupt of the last transmit data.
p.506
UART
transmission (in
continuous
transmission
mode)
After setting the PER0 register to 1, be sure to set the SPSm register after 4 or more
clocks have elapsed.
p.507
For the UART reception, be sure to set SMRmr of channel r that is to be paired with
channel n.
pp.509,
510
UART reception
After setting the PER0 register to 1, be sure to set the SPSm register after 4 or more
clocks have elapsed.
pp.511,
514
UART (UART0,
UART1,
UART2,
UART3)
communication
Calculating baud
rate
Setting SDRmn [15:9] = (0000000B, 0000001B) is prohibited.
p.523
Address field
transmission
After setting the PER0 register to 1, be sure to set the SPSm register after 4 or more
clocks have elapsed.
p.531
Data reception
ACK is not output when the last data is received (NACK). Communication is then
completed by setting “1” to the STmn bit to stop operation and generating a stop
condition.
p.540
Chapter
1
3
Soft
Simplified
I
2C (IIC10,
IIC20)
communi-
cation
Calculating
transfer rate
Setting SDRmn[15:9] = 0000000B is prohibited. Setting SDRmn[15:9] = 0000001B or
more.
p.542
Do not write data to IIC0 during data transfer.
p.558
IIC0: IIC shift
register 0
Write or read IIC0 only during the wait period. Accessing IIC0 in a communication
state other than during the wait period is prohibited. When the device serves as the
master, however, IIC0 can be written only once after the communication trigger bit
(STT0) is set to 1.
p.558
PER0:
Peripheral
enable register 0
When setting serial interface IIC0, be sure to set IIC0EN to 1 first. If IIC0EN = 0,
writing to a control register of serial interface IIC0 is ignored, and, even if the register
is read, only the default value is read (except for port mode register 6 (PM6) and port
register 6 (P6)).
p.561
The start condition is detected immediately after I
2C is enabled to operate (IICE0 = 1)
while the SCL0 line is at high level and the SDA0 line is at low level. Immediately
after enabling I
2C to operate (IICE0 = 1), set LREL0 (1) by using a 1-bit memory
manipulation instruction.
p.562
IICC0: IIC
control register 0
When bit 3 (TRC0) of IIC status register 0 (IICS0) is set to 1, WREL0 is set to 1
during the ninth clock and wait is canceled, after which TRC0 is cleared and the
SDA0 line is set to high impedance.
p.565
Write to STCEN only when the operation is stopped (IICE0 = 0).
p.569
As the bus release status (IICBSY = 0) is recognized regardless of the actual bus
status when STCEN = 1, when generating the first start condition (STT0 = 1), it is
necessary to verify that no third party communications are in progress in order to
prevent such communications from being destroyed.
p.569
IICF0: IIC flag
register 0
Write to IICRSV only when the operation is stopped (IICE0 = 0).
p.569
IICX0: IIC
function
expansion
register 0
Determine the transfer clock frequency of I
2C by using CLX0, SMC0, CL01, and CL00
before enabling the operation (by setting bit 7 (IICE0) of IIC control register 0 (IICC0)
to 1). To change the transfer clock frequency, clear IICE0 once to 0.
p.571
Chapter
1
4
Soft
Serial
interface
IIC0
Setting transfer
clock
Determine the transfer clock frequency of I
2C by using CLX0, SMC0, CL01, and CL00
before enabling the operation (by setting bit 7 (IICE0) of IIC control register 0 (IICC0)
to 1). To change the transfer clock frequency, clear IICE0 once to 0.
p.577