M38203M4 Datasheet, PDF (239/344 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.6 Serial I/O2
[Notes on use]
Notes 1: When SRDY2 signal output is not used, set the SRDY2 output enable bit (bit 4) to
“0” in  below.
2: In the duplex data transfer mode, write transmit data in ‘ below.
3: To use a serial I/O2 interrupt, set in the following sequence.
4: When no serial I/O2 interrupt is used, omit settings Œ, Ž, ,  and ’ below.
ŒDisable Serial I/O2 interrupt
b7
b0
00
ICON2: Interrupt control register 2 [Address 3F16]
b6: Serial I/O2 interrupt enable bit
0: Interrupts disabled
Setting of serial I/O2 control register
Selection of serial I/O2, or others
b7
b0
1
SIO2CON: Serial I/O2 control register [Address 1D16]
b2–b0: Internal synchronization clock select bits
000: f(XIN)/8 _{011: f(XIN)/64}
001: f(XIN)/16 _{110: f(XIN)/128}
010: f(XIN)/32 _{111: f(XIN)/256}
b3: Serial I/O2 port selection bit
1: SOUT2, SCLK2 signal output
b4: SRDY2 output enable bit
0: I/O port
1: SRDY2 signal output
b5: Transfer direction selection bit
0: LSB first
1: MSB first
b6: Synchronization clock selection bit
0: External clock
1: Internal clock
: Nothing is allocated
ŽOne or more instructions (e.g., NOP) after 
Set the serial I/O2 interrupt request to “0”
b7
b0
0
IREQ2: Interrupt request register 2 [Address 3D16]
b6: Serial I/O2 interrupt request bit
0: No interrupts request issued
: Nothing is allocated
Enable serial I/O2 interrupt
b7
b0
01
ICON2: Interrupt control register 2 [Address 3F16]
b6: Serial I/O2 interrupt enable bit
1: Interrupts enabled
‘Set dummy data to serial I/O2 register SIO2 [Address 1F16]
(When SRDY2 is used, “L” is output from the P53/SRDY2 pin)
’Processing of serial I/O2 interrupt
Fig. 2.6.12 Receiving method of serial I/O2
3820 GROUP USER’S MANUAL
2–153