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MC80F0204 Datasheet, PDF (72/126 Pages) List of Unclassifed Manufacturers – 8-BIT SINGLE-CHIP MICROCONTROLLERS
MC80F0104/0204
Preliminary
Serial I/O Mode Register (SIOM) controls serial I/O func-
tion. According to SCK1 and SCK0, the internal clock or
external clock can be selected.
Serial I/O Data Register (SIOR) is an 8-bit shift register.
First LSB is send or is received.
SIOM
R/W R/W R/W R/W R/W R/W R/W R
7
6
5
4
3
2
1
0
POL IOSW SM1 SM0 BSTCCKL1 SCK0 SIOST SIOSF
ADDRESS: 0E2H
INITIAL VALUE: 0000 0001B
Serial transmission status bit
0: Serial transmission is in progress
1: Serial transmission is completed
Serial transmission start bit
Setting this bit starts an Serial transmission.
After one cycle, bit is cleared to “0” by hardware.
Serial transmission Clock selection
00: fXIN ÷ 4
01: fXIN ÷ 16
10: TMR0OV(Timer0 Overflow)
11: External Clock
Serial transmission Operation Mode
00: Normal Port(R42,R43,R44)
01: Sending Mode(SCK,R43,SO)
10: Receiving Mode(SCK,SI,R44)
11: Sending & Receiving Mode(SCK,SI,SO)
Serial Input Pin Selection bit
0: SI Pin Selection
1: SO Pin Selection
SIOR
Serial Clock Polarity Selection bit
0: Data Transmission at Falling Edge
Received Data Latch at Rising Edge
1: Data Transmission at Rising Edge
Received Data Latch at Falling Edge
R/W R/W R/W R/W R/W R/W R/W R/W
76543210
BTCL
ADDRESS: 0E3H
INITIAL VALUE: Undefined
Sending Data at Sending Mode
Receiving Data at Receiving Mode
Figure 15-2 SIO Control Register
15.1 Transmission/Receiving Timing
The serial transmission is started by setting SIOST(bit1 of
SIOM) to “1”. After one cycle of SCK, SIOST is cleared
automatically to “0”. At the default state of POL bit clear,
the serial output data from 8-bit shift register is output at
falling edge of SCLK, and input data is latched at rising
edge of SCLK pin (Refer to Figure 15-3 ). When transmis-
sion clock is counted 8 times, serial I/O counter is cleared
as ‘0”. Transmission clock is halted in “H” state and serial
I/O interrupt (SIOIF) occurred.
68
Mar. 2005 Ver 0.2