OPERATION GUIDE
.
OG_STD-502-R_v09e
Circuit Design, Inc.
7
Terminal
Terminal
Input/
Input/Output level (V)
No.
name
Output
Low
Hi
Internal equivalent circuit
Output
0 to 0.25
Vref -0.4 to Vref
5
RXD
The output terminal for serial communication.
Settings for serial communication
Baud rate
19.2 kbps
Character bits
8 bits
Parity
none
Stop bits
2 bits
Output
0 to 0.25
Vref -0.4 to Vref
6
DO
The RX data output terminal.
Outputs RX data in synchronization with the clock
from the RX-CLK.
The DO data should be read at the rising clock
edge of the RX-CLK
Input
0 to 0.25
Vref -0.4 to Vref
7
DI
The TX data input terminal.
Inputs TX data in synchronization with the clock
from the TX-CLK.
Data should be set to the DI at the falling clock
edge of the TX-CLK.
Input
0 - 0.3
Vcc -0.4 to Vcc
8
TXRX
SEL
The terminal for switching the TX mode and RX
mode.
Setting this terminal to ‘L’ enables the TX mode
and setting to ‘H’ enables the RX mode.
Input
0 - 0.3
Vcc -0.4 to Vcc
9
NC
Sets the STD-502-R into RF-standby state.
Setting this terminal to L enables normal operation
and setting to H enables RF-standby.
RF-standby can be used to reduce the current
consumption.
Input
3.1
5.5
10
Vref
The input terminal for interface reference voltage.
Communication can be performed using the
voltage level applied to this terminal.
Terminal
Termin
1
M
Ω
C
P
U
Terminal
Level
Translator
Level
Translator
Level
Translator
Terminal
Termin
al
1
M
Ω
C
P
U
