CHAPTER 10 SERIAL INTERFACE FUNCTION
User’s Manual U13850EJ4V0UM
315
(1) Asynchronous serial interface mode registers 0, 1 (ASIM0, ASIM1)
ASIMn is an 8-bit register that controls UARTn’s serial transfer operations.
ASIMn can be set by an 8-/1-bit memory manipulation instruction.
RESET input clears these registers to 00H.
Figure 10-33. Asynchronous Serial Interface Mode Registers 0, 1 (ASIM0, ASIM1)
After reset:
00H
R/W
Address: FFFFF300H, FFFFF310H
<7>
<6>
5
4
3
2
1
0
ASIMn
TXEn
RXEn
PS1n
PS0n
UCLn
SLn
ISRMn
0
(n = 0, 1)
TXEn
RXEn
Operation mode
RXDn/Pxx pin function
TXDn/Pxx pin function
0
0
Operation stop
Port function
Port function
0
1
UARTn mode (receive only)
Serial function
Port function
1
0
UARTn mode (transmit only)
Port function
Serial function
1
1
UARTn mode (transmit and receive)
Serial function
Serial function
PS1n
PS0n
Parity bit specification
0
0
No parity
0
1
Zero parity always added during transmission
No parity detection during reception (parity errors do not occur)
1
0
Odd parity
1
1
Even parity
UCLn
Character length specification
0
7 bits
1
8 bits
SLn
Stop bit length specification for transmit data
0
1 bit
1
2 bits
ISRMn
Receive completion interrupt control when error occurs
0
Receive completion interrupt is issued when an error occurs
1
Receive completion interrupt is not issued when an error occurs
Caution Do not switch the operation mode until after the current serial transmit/receive operation has
stopped.