Data Mode AT COMMANDS

The DTE implements the escape sequence by sending the escape character (as defined in S2) three times, followed by a valid AT command, and then the contents of S3 (typically a <CR>). Upon detecting the three consecutive escape characters, the modem changes to TIES command mode and starts an internal EPD (Escape Prompt Delay) timer (with the time limit defined by S12). The modem then looks for one of the following conditions to occur:

•No additional data is received and the EPD timer times out: the modem sends an ‘OK’ message to the DTE and then waits indefinitely for an incoming valid AT command string from the DTE. Until the modem receives a valid AT command, it monitors any data received from the DTE and passes on the data to the remote modem (that is, the modem does not echo back the received character to the DTE).

—If the subsequent character received by the modem is not an ‘A’ or ‘a’, the modem returns to data mode and sends a ‘CONNECT’ message back to the DTE.

—If the modem receives an ‘A’ or ‘a’, it stores any additional data received from the DTE in the modem’s internal command buffer and continues to send the data to the remote modem. The modem then waits until the DTE sends a <CR>, or up to 39 data characters, before deciding whether to go to command mode or to return to data mode. Upon detecting a <CR> or receiving the 39 data characters, the modem determines if a valid AT command has been received. If a non-AT command string or an invalid command string has been received, then the modem changes back to data mode and sends a ‘CONNECT’ message to the DTE. If a valid AT command has been received, the modem changes to command mode and sends an ‘OK’ message. After sending the ‘OK’ message, the modem echoes any received data from the DTE while in command mode.

•An ‘A’ or ‘a’ is received from the DTE. The modem disables the EPD timer and sends the character to the remote modem. The modem then stores any received data from the DTE into the modem internal command buffer and sends the data to the remote modem. Upon detecting a <CR> or receiving up to 39 data characters, the modem determines if a valid AT command has been received; if so, it processes the valid commands. If a non-AT command string or an invalid command string has been received, then the modem remains in data mode. If a valid AT command has been received, then the modem changes to command mode and sends an ‘OK’ message. After sending this, the modem (while in command mode) echoes back any data received from the DTE.

•Any character except an ‘A’ or ‘a’ is received from the DTE. The modem disables the EPD timer and changes back to data mode.

If an AT command string is received while in TIES command mode, the modem processes any valid AT command. Upon detecting an invalid AT command, the modem changes back to data mode and issues a ‘CONNECT’ message to the DTE. While in TIES command mode, the modem ignores certain characters that may cause the modem to incorrectly decide that an incoming AT string is invalid. The ignore characters are <LF>, <space>, and <CR> (<CR> is ignored only when S3 is not equal to <CR>). Not all AT commands are supported during TIES command mode. The following is a list of supported commands:

En, Hn, Mn, On, Qn, Sn, Vn, Xn, and ‘&’ commands (except &Tn and &F)

The escape character is determined by the value stored in S-register S2, and it is typically a ‘+’ character. The following is an example of the TIES Escape Sequence:

Format:

<char1><char2><char3><AT command><contents of S3>

char1 = char2 = char3 = escape character (S2)

Example:

536EX Chipset Developer’s Manual

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Intel Confidential

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Intel 537EX manual Example
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537EX specifications

The Intel 537EX is a powerful and innovative embedded processor designed for a range of applications, particularly in the fields of industrial automation, telecommunications, and transport management systems. This processor is a member of Intel's embedded product line, tailored specifically to meet the demands of systems that require high reliability and long lifecycle support.

One of the main features of the Intel 537EX is its multi-core architecture, which enables efficient parallel processing capabilities. This allows for the execution of multiple tasks simultaneously, significantly improving overall system performance. The processor also incorporates Intel’s advanced power management technology, which ensures that the device consumes energy efficiently, enhances thermal performance, and prolongs the lifespan of the system.

The Intel 537EX supports a range of connectivity options, including high-speed Ethernet and Serial ATA interfaces. This ensures that it can easily integrate into existing systems, seamlessly supporting applications that require robust data transfer capabilities. Additionally, the processor is equipped with multiple I/O ports, facilitating the connection of various peripherals and sensors, which is crucial in industrial applications.

One of the standout technologies within the Intel 537EX is its support for hardware virtualization. This feature allows for the creation of multiple virtual environments within a single physical structure, optimizing resource utilization and enhancing system flexibility. Additionally, Intel’s integrated security technologies provide a significant layer of protection against potential threats, ensuring that embedded systems remain secure.

Another characteristic of the Intel 537EX is its extensive software support, which includes compatibility with various operating systems and development environments. This versatility makes it an attractive choice for developers looking to build or upgrade their embedded systems. With access to Intel's comprehensive software tools, developers can quickly optimize applications to take full advantage of the processor's capabilities.

The Intel 537EX also boasts excellent thermal performance, allowing it to operate efficiently in harsh environments. This is crucial for embedded applications in industrial settings where temperature fluctuations are common. Overall, the Intel 537EX is engineered to deliver high-performance processing power, superior connectivity, and enhanced security, solidifying its position as a reliable choice for demanding embedded applications.
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