3874 Group User's Manual
APPLICATION
2-119
2.5 Serial I/O
2.5.12 8-bit serial I/O mode
In the 8-bit serial I/O mode, the serial I/O synchronous transmit/receive of 8-bit data is performed.
(1)
8-bit serial I/O mode setting method
Figures 2.5.43 and 2.5.44 show the 8-bit serial I/O mode setting method.
Fig. 2.5.43 8-bit serial I/O mode setting method (1)
Process 1: Disable the serial I/O3 interrupt.
Process 2: Set serial I/O3 control register 1
b7
b0
Interrupt control register 2
(ICON2: address 3F16)
CNTR0, serial I/O3 interrupts disabled
(Interrupt of each vector disabled)
Process 3: Set serial I/O3 control register 2
b7
b0
Serial I/O3 control register 2
(SIO3CON2: address 1516)
P85/SRDY3P86/SBUSY3 pin control
0000: P85, P86 pins are I/O ports.
0001: Not used
0010: P85 pin is SRDY3 output, P86 pin is I/O port.
0011: P85 pin is SRDY3 output, P86 pin is I/O port.
0100: P85 pin is I/O port, P86 pin is SBUSY3 input.
0101: P85 pin is I/O port, P86 pin is SBUSY3 input.
0110: P85 pin is I/O port, P86 pin is SBUSY3 output.
0111: P85 pin is I/O port, P86 pin is SBUSY3 output.
1000: P85 pin is SRDY3 input, P86 pin is SBUSY3 output.
1001: P85 pin is SRDY3 input, P86 pin is SBUSY3 output.
1010: P85 pin is SRDY3 input, P86 pin is SBUSY3 output.
1011: P85 pin is SRDY3 input, P86 pin is SBUSY3 output.
1100: P85 pin is SRDY3 output, P86 pin is SBUSY3 input.
1101: P85 pin is SRDY3 output, P86 pin is SBUSY3 input.
1110: P85 pin is SRDY3 output, P86 pin is SBUSY3 input.
1111: P85 pin is SRDY3 output, P86 pin is SBUSY3 input.
P82/SOUT3P84/SCLK3 P-channel output control
0: CMOS 3 state output
1: N-channel open-drain output
(1) Disable interrupt of each vector
0
b7
b0
0
Interrupt source discrimination control register 2
(ICOND2: address 3716)
Serial I/O3 interrupt disabled
(2) Disable interrupt of each interrupt factor
b7
b0
Serial I/O3 control register 1
(SIO3CON1: address 1416)
Serial I/O disabled (P82 to P87 pins are I/O ports.)
Serial I/O3 synchronous clock selected
00: Internal synchronous clock (P87 pin is I/O port.)
01: External synchronous clock (P87 pin is I/O port.)
10: Internal synchronous clock (P87 pin is SSTB3 output.)
11: Internal synchronous clock (P87 pin is SSTB3 output.)
Transfer mode selected
0: Full-duplex transfer mode
1: Transmit-only mode
Serial I/O3 transfer direction selected
0: LSB first
1: MSB first
00 0