Service Manual

Interface Description EMIII-DUAL Servce Manual Application Information
EMIII-DUAL V1.0 AnyDATA.NET Proprietary – Use Subject to Restrictions
4. Level Translator Part
4.1 EMIII-DUAL supply power to Modem(4.0V).
[Fig 4-1] The Block Diagram of Source (in brief)
4.2 UART Interface
The Universal Asynchronous Receiver Transmitter (UART) communicates with serial data that
conforms the RS-232 Interface protocol. The modem provides 3.0V CMOS level outputs and 3.0V
CMOS switching input level. And all inputs have 5.0V tolerance but 3.0V or 3.3V CMOS logic
compatible signals are highly recommended.
All the control signals of the RS-232 signals are active low, but data signals of RXD, and TXD are
active high.
The UART has a 64byte transmit (TX) FIFO and a 64byte receive (RX) FIFO. The UART Features
hardware handshaking, programmable data sizes, programmable stop bits, and odd, even, no parity.
The UART operates at a 115.2kbps maximum bit rate.
4.2.1 UART Inter Pinouts
NAME DESCRIPTION CHARACTERISTIC
DP_DCD/ Data Carrier Detect Network connected from the modem
DP_RI/ Ring Indicator Output to host indicating coming call
DP_RTS/ Request to Send Ready for receive from host
DP_TXD Transmit Data Output data from the modem
DP_DTR/ Data Terminal Ready Host ready signal
DP_RXD Receive Data Input data to the modem
DP_CTS/ Clear to Send Modem output signal