User's Manual
Table Of Contents
- Contents
- Tables
- Figures
- 1 Introduction
- 2 Interface Characteristics
- 2.1 Application Interface
- 2.1.1 Pad Assignment
- 2.1.2 Signal Properties
- 2.1.3 USB Interface
- 2.1.4 Serial Interface ASC0
- 2.1.5 Serial Interface ASC1
- 2.1.6 UICC/SIM/USIM Interface
- 2.1.7 Digital Audio Interface
- 2.1.8 Pulse Code Modulation Interface (PCM)
- 2.1.9 Inter IC Sound Interface (I2S)
- 2.1.10 GPIO Interface
- 2.1.11 I2C Interface
- 2.1.12 SPI Interface
- 2.1.13 Pulse Counter
- 2.1.14 HSIC Interface (ELS51-VA Only)
- 2.1.15 SDIO Interface (ELS51-VA Only)
- 2.1.16 Control Signals
- 2.2 RF Antenna Interface
- 2.3 Sample Application
- 2.1 Application Interface
- 3 Operating Characteristics
- 3.1 Operating Modes
- 3.2 Power Up/Power Down Scenarios
- 3.3 Power Saving
- 3.4 Power Supply
- 3.5 Operating Temperatures
- 3.6 Electrostatic Discharge
- 3.7 Blocking against RF on Interface Lines
- 3.8 Reliability Characteristics
- 4 Mechanical Dimensions, Mounting and Packaging
- 5 Regulatory and Type Approval Information
- 6 Document Information
- 7 Appendix
Cinterion
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ELS31-VA/ELS51-VA Hardware Interface Description
2.1 Application Interface
56
ELS31-VA_ELS51-VA_HID_v01.000 2017-01-04
Confidential / Preliminary
Page 27 of 106
2.1.5 Serial Interface ASC1
ELS31-VA/ELS51-VA provides a 4-wire unbalanced, asynchronous modem interface ASC1
conforming to ITU-T V.24 protocol DCE signaling. 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). For electrical characteristics please refer to Table 2. For an illustra-
tion of the interface line’s startup behavior see Figure 9. ASC1 can only be used as data inter-
face.
The ASC1 interface lines are originally available as GPIO lines. If configured as ASC1 lines,
the GPIO lines are assigned as follows: GPIO16 --> RXD1, GPIO17 --> TXD1, GPIO18 -->
RTS1 and GPIO19 --> CTS1. Configuration is done by AT command (see [1]: AT^SCFG). The
configuration is non-volatile and becomes active after a module restart.
ELS51-VA 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 8: 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 4800 bps to 921600 bps.
• Supports RTS1/CTS1 hardware flow control. Communication is possible by using only RXD
and TXD lines, if RTS1 is pulled low.
• Wake up from SLEEP mode by RTS0 activation (high to low transition; see Section 3.3.2).
AT commands for signaling are not supported on ASC1 interface. ASC1 is intended only for
data transfer in a Linux environment.
The following figure shows the startup behavior of the asynchronous serial interface ASC1.