User's Manual

EHS5-E/EHS5-US Hardware Interface Overview
2.1 Application Interface
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EHS5_HIO_v01.000 Page 12 of 35 2012-11-14
Confidential / Preliminary
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• The RING0 signal serves to indicate incoming calls and other types of URCs (Unsolicited
Result Code). It can also be used to send pulses to the host application, for example to
wake up the application from power saving state.
• Configured for 8 data bits, no parity and 1 stop bit.
• ASC0 can be operated at fixed bit rates from 1200bps up to 921600bps.
• Autobauding supports bit rates from 1200bps up to 230400bps.
• Supports RTS0/CTS0 hardware flow control.
• Wake up from SLEEP mode by RTS0 activation (high to low transition).
2.1.3 Serial Interface ASC1
EHS5-E/EHS5-US offers a 4-wire unbalanced, asynchronous modem interface ASC1 conform-
ing to ITU-T V.24 protocol DCE signalling. The electrical characteristics do not comply with ITU-
T V.28. The significant levels are 0V (for low data bit or active state) and 1.8V (for high data bit
or inactive state).
EHS5-E/EHS5-US is designed for use as a DCE. Based on the conventions for DCE-DTE con-
nections it communicates with the customer application (DTE) using the following signals:
• Port TXD @ application sends data to module’s TXD1 signal line
• Port RXD @ application receives data from the module’s RXD1 signal line
Figure 4: Serial interface ASC1
Features
• Includes only the data lines TXD1 and RXD1 plus RTS1 and CTS1 for hardware hand-
shake.
• On ASC1 no RING line is available.
• Configured for 8 data bits, no parity and 1 or 2 stop bits.
• ASC1 can be operated at fixed bit rates from 1,200 bps to 921600 bps. Autobauding is not
supported on ASC1.
• Supports RTS1/CTS1 hardware flow.