MC80F0204 Datasheet, PDF (71/126 Pages) List of Unclassifed Manufacturers – 8-BIT SINGLE-CHIP MICROCONTROLLERS

Preliminary
MC80F0104/0204
15. SERIAL INPUT/OUTPUT (SIO)
The serial Input/Output is used to transmit/receive 8-bit
data serially. The Serial Input/Output (SIO) module is a se-
rial interface useful for communicating with other periph-
eral of microcontroller devices. These peripheral devices
may be serial EEPROMs, shift registers, display drivers,
A/D converters, etc. This SIO is 8-bit clock synchronous
type and consists of serial I/O data register, serial I/O mode
register, clock selection circuit, octal counter and control
circuit as illustrated in Figure 15-1 . The SO pin is designed
to input and output. So the Serial I/O(SIO) can be operated
with minimum two pin. Pin R00/SCK, R01/SI, and R02/
SO pins are controlled by the Serial Mode Register. The
contents of the Serial I/O data register can be written into
or read out by software. The data in the Serial Data Regis-
ter can be shifted synchronously with the transfer clock
signal.
X_IN PIN
Timer0
Overflow
SCK PIN
SO PIN
SIOST
SIOSF
SCK[1:0]
÷4
00
÷ 16
01
10
11
“11” _MUX
not “11”
SCK[1:0]
SM0
POL
“0”
“1”
IOSW
Start
Complete
SIO
Clock ^CONTROL
CIRCUIT
Clock
SOUT
clear
overflow
Octal
Counter
(3-bit)
SIOIF
Serial communication
Interrupt
IOSW
1
SI PIN
0
Input shift register
Shift
SIOR
Internal Bus
Figure 15-1 SIO Block Diagram
Mar. 2005 Ver 0.2
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