M38002M4 Datasheet, PDF (82/173 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.3 Serial I/O
Control procedure : Figure 2.3.17 shows a control procedure at a transmitting side, and Figure
2.3.18 shows a control procedure at a receiving side.
RESET
q X : This bit is not used in this application.
Set it to “0” or “1.” It’s value can be disregarded.
Initialization
SIOCON ^{(Address : 1A16)} 1101XX002
BRG
(Address : 1C16)
8–1
INTEDGE (Address : 3A16), bit0 0
0
IREQ1 (Address : 3C16), bit0?
1
IREQ1 (Address : 3C16), bit0 0
q _{Detect INT0 falling edge}
TB/RB (Address : 1816)
The first byte of a
transmission data
q _{Write a transmission data}
The Transmit buffer empty flag is set to “0”
by this writing.
SIOSTS (Address : 1916), bit0?
0
1
TB/RB (Address : 1816)
The second byte of a
transmission data
q _{Check to be transfered data from the Transmit}
buffer register to the Transmit shift register.
(Transmit buffer empty flag)
qWrite a transmission data
The Transmit buffer empty flag is set to “0”
by this writing.
0
SIOSTS (Address : 1916), bit0?
1
q _{Check to be transfered data from the Transmit}
buffer register to the Transmit shift register.
(Transmit buffer empty flag)
SIOSTS (Address : 1916), bit2?
0
q _{Check a shift completion of the Transmit shift register}
(Transmit shift register shift completion flag)
1
Fig. 2.3.17 Control procedure at a transmitting side [Communication using a clock synchronous
serial I/O]
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3800 GROUP USER’S MANUAL