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CHAPTER 16 SERIAL INTERFACE UART0
User’s Manual U15798EJ2V0UD
(5) Receive controller
The receive controller controls receive operations based on the values set to asynchronous serial interface mode
register 0 (ASIM0). During a receive operation, it performs error checking, such as for parity errors, and sets
various values to asynchronous serial interface status register 0 (ASIS0) according to the type of error that is
detected.
16.3 Registers to Control Serial Interface UART0
Serial interface UART0 is controlled by the following three types of registers.
• Asynchronous serial interface mode register 0 (ASIM0)
• Asynchronous serial interface status register 0 (ASIS0)
• Baud rate generator control register 0 (BRGC0)
(1) Asynchronous serial interface mode register 0 (ASIM0)
This is an 8-bit register that controls serial interface UART0’s serial transfer operations.
ASIM0 is set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets the value of this register to 00H.
Figure 16-3 shows the format of ASIM0.
Caution In UART mode, set the port mode register (PMXX) as follows. Set the output latch of a port set
to output mode (PMXX = 0) to 0.
•
During receive operation
Set P26 (R
X
D0) to input mode (PM26 = 1)
•
During transmit operation
Set P27 (T
X
D0) to output mode (PM27 = 0)
•
During transmit/receive operation
Set P26 to input mode, and P27 to output mode
