22
3819 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
MITSUBISHI MICROCOMPUTERS
SERIAL I/O
The 3819 group has built-in 8-bit clock synchronized serial I/O
3
channels (serial I/O1, serial I/O2, and serial I/O3).
Serial I/O1 builds in the automatic transfer function. The function
can be switched to the serial I/O ordinary mode with the serial I/O
automatic transfer control register (address 001A
16
).
Serial I/O2 and Serial I/O3 can be used only in the serial I/O ordi-
nary mode.
The I/O pins of the serial I/O function are also used as I/O ports
P5 and P6
4
–P6
7
, and their operation is selected with the serial I/O
control registers (addresses 0019
16
, 001D
16
, and 001E
16
).
Serial I/O Control Registers
(SIO1CON, SIO2CON, SIO3CON)
0019
16
, 001D
16
, 001E
16
Each of the serial I/O control registers (addresses 0019
16
,
001D
16
, and 001E
16
) consists of 8 selection bits which control the
serial I/O function.