Technical information

2-28
3800 GROUP USER’S MANUAL
APPLICATION
2.3 Serial I/O
2.3.3 Serial I/O connection examples
(1) Control of peripheral IC equipped with CS pin
There are connection examples using a clock synchronous serial I/O mode.
Figure 2.3.10 shows connection examples of a peripheral IC equipped with the CS pin.
Fig. 2.3.10 Serial I/O connection examples (1)
Port
CS
CLK
IN
OUT
(4) Connecting ICs
3800 group
Peripheral IC 1
Peripheral IC 2
Port
S
CLK
TXD
R
XD
CS
CLK
IN
OUT
(2) Transmission and reception
3800 group Peripheral IC
(E PROM etc.)
2
(3) Transmission and reception
(Pins R
XD and TXD are connected)
(Pins IN
and OUT in peripheral IC
are connected)
CS
CLK
IN
OUT
3800 group
Peripheral IC
(E PROM etc.)
2
✻2
“Port” is an output port controlled by software.
Note:
Port
S
CLK
TXD
CS
CLK
DATA
(1) Only transmission
(using the R
XD pin as an I/O port)
3800 group Peripheral IC
(OSD controller etc.)
✻1
✻
1: Select an N-channel open-drain output control of TXD pin.
2: Use such OUT pin of peripheral IC as an N-channel open-
drain output in high impedance during receiving data.
Port
S
CLK
TXD
R
XD
S
CLK
TXD
R
XD
Port
CS
CLK
IN
OUT