Technical information

2-34
3800 GROUP USER’S MANUAL
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.
Fig. 2.3.17 Control procedure at a transmitting side [Communication using a clock synchronous
serial I/O]
RESET
Initialization
SIOCON
BRG
INTEDGE
.....
TB/RB (Address : 1816)
The first byte of a
transmission data
Write a transmission data
The Transmit buffer empty flag is set to “0”
by this writing.
Detect INT0 falling edge
IREQ1 (Address : 3C
16), bit0?
1
0
Check to be transfered data from the Transmit
buffer register to the Transmit shift register.
(Transmit buffer empty flag)
SIOSTS (Address : 19
16), bit0?
1
0
TB/RB (Address : 1816)
Write a transmission data
The Transmit buffer empty flag is set to “0”
by this writing.
The second byte of a
transmission data
Check to be transfered data from the Transmit
buffer register to the Transmit shift register.
(Transmit buffer empty flag)
SIOSTS (Address : 19
16), bit0?
1
0
Check a shift completion of the Transmit shift register
(Transmit shift register shift completion flag)
SIOSTS (Address : 19
16), bit2?
1
0
IREQ1 (Address : 3C16), bit0
0
● X : This bit is not used in this application.
Set it to “0” or “1.” It’s value can be disregarded.
●
●
●
●
●
●
(Address : 1A16)
(Address : 1C
16)
(Address : 3A
16), bit0
8–1
0
1101XX00
2