User Manual
Table Of Contents
EHS6 Hardware Interface Overview
2.1 Application Interface
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EHS6_HIO_v01.441 Page 12 of 38 2013-07-11
Confidential / Preliminary
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 1,200bps up to 921,600bps.
• Autobauding supports bit rates from 1,200bps up to 230,400bps.
• Supports RTS0/CTS0 hardware flow control. The hardware hand shake line RTS0 has an
internal pull down resistor causing a low level signal, if the line is not used and open.
Although hardware flow control is recommended, this allows communication by using only
RXD and TXD lines.
• Wake up from SLEEP mode by RTS0 activation (high to low transition).
2.1.3 Serial Interface ASC1
Four EHS6 GPIO lines can be configured as ASC1 interface signals to provide a 4-wire unbal-
anced, asynchronous modem interface ASC1 conforming to ITU-T V.24 protocol DCE signal-
ling. 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).
EHS6 is designed for use as a DCE. Based on the conventions for DCE-DTE connections 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 921,600 bps.
• Autobauding supports bit rates from 1,200bps up to 230,400bps.
• Supports RTS1/CTS1 hardware flow. The hardware hand shake line RTS0 has an internal
pull down resistor causing a low level signal, if the line is not used and open. Although hard-
ware flow control is recommended, this allows communication by using only RXD and TXD
lines.