User's Manual

Interface Description EMIII-DUAL Reference Manual Application Information
EMIII-DUAL V1.0 AnyDATA.NET Proprietary – Use Subject to Restrictions
4. Interface Descriptions
4.1 Overview
This chapter covers information required to design the EMIII-DUAL into a subscriber unit
application. In addition, the internal signals that are necessary for complete understanding of the UART
interfaces are described below.
4.2 RS232 Interface (Standard)
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 3.3VCMOS 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.
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
GND
Signal Ground Signal ground
Figure 4-1 UART Interface Pinouts