NEC NEC PD78081(A), User Manual

Page: 164 / 274

141
CHAPTER 11 SERIAL INTERFACE CHANNEL 2
6 5 4 3 2 1 0 7
Symbol
ASIM TXE RXE PS1 PS0 CL SL ISRM SCK FF70H 00H R/W
Address After Reset R/W
SCK
0
1
Clock Selection in Asynchronous Serial Interface
Mode
Input clock from off-chip to ASCK pin
Dedicated baud rate generator output
Note
ISRM
0
1
Control of Reception Completion Interrupt in Case
of Error Generation
Reception completion interrupt generated in case
of error generation
Reception completion interrupt not generated in
case of error generation
SL Transmit Data Stop Bit Length Specification
CL
1
Character Length Specification
7 bits
8 bits
RXE
0
1
Receive Operation Control
Receive operation stopped
Receive operation enabled
TXE
0
1
Transmit Operation Control
Transmit operation stopped
Transmit operation enabled
PS1
0
1
0 1 bit
1 2 bits
0
Parity Bit Specification
No Parity
Even parity
PS0
0
1
0 parity always added in transmission
No parity test in reception (parity error not
generated)
0 1
1 Odd parity 0
Note When SCK is set to 1 and the baud rate generator output is selected, the ASCK pin can be used as
an input/output port.
Cautions 1. When the 3-wire serial I/O mode is selected, 00H should be set in ASIM.
2. The serial transmit/receive operation must be stopped before changing the operating
mode.
(2) Asynchronous serial interface mode register (ASIM)
This register is set when serial interface channel 2 is used in the asynchronous serial interface mode.
ASIM is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets ASIM to 00H.
Figure 11-4. Asynchronous Serial Interface Mode Register Format