CHAPTER 11 SERIAL INTERFACE FUNCTION
User’s Manual U15109EJ3V0UD
437
(1) Asynchronous serial interface mode registers 0 to 3 (ASIM0 to ASIM3)
ASIMn is an 8-bit register that controls UARTn’s serial transfer operations.
ASIMn can be set by an 8-bit or 1-bit memory manipulation instruction.
RESET input sets these registers to 00H.
After reset:
00H
R/W
Address: ASIM0:
FFFFF300H
ASIM1:
FFFFF310H
ASIM2:
FFFFF230H
ASIM3:
FFFFF2B0H
<7>
<6>
5
4
3
2
1
0
ASIMn
TXEn
RXEn
PS1n
PS0n
UCLn
SLn
ISRMn
0
(n = 0 to 3)
TXEn
RXEn
Operating mode
RXDn/Pxx pin
function
TXDn/Pxx pin
function
0
0
Operation stopped
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
Cautions 1. Do not switch the operating mode until after the current serial transmit/receive operation
has stopped.
2. Receive error interrupts are not provided in the V850/SC1, V850/SC2, and V850/SC3. To
detect receive errors, always set ISRMn to 0.
3. Always set bit 0 to 0.