ADLINK Technology ReadyBoard 620, Reference Manual

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Chapter 3 Hardware
ReadyBoard 620 Reference Manual 31
Remote Access (Serial Console)
The ReadyBoard 620 supports the Remote Access (serial console or console redirection) feature. The
remote access (serial console) can be accessed by an ANSI-compatible serial terminal, or the equivalent
terminal emulation software running on another system. This can be very useful when setting up the BIOS
on a production line for systems that are not connected to a keyboard and display.
Serial Console Setup
The serial console feature is implemented by connecting a standard null modem cable or a modified serial
cable (or “Hot Cable”) between one of the serial ports, such as Serial 1 (J6A), and the serial terminal or a PC
with communications software. The BIOS Setup Utility controls the serial console settings on the
ReadyBoard 620. Refer to Chapter 4, BIOS Setup Utility to set the serial console option, using a serial
terminal, or PC with communications software.
Hot (Serial) Cable
To convert a standard serial cable to a Hot Cable, certain pins must be shorted together at the Serial port
connector or on the DB9 connector. For example, short the RTS (7) and RI (9) on the respective DB9 port
connector as shown in Figure 3-3 .
Figure 3-3. Hot Cable Jumper
Watchdog Timer (WDT)
The watchdog timer (WDT) restarts the system if an error or mishap occurs, allowing the system to recover
from the mishap, even though the error condition may still exist. Possible problems include failure to boot
properly, loss of control by the application software, failure of an interface device, unexpected conditions on
the bus, or other hardware or software malfunctions.
The WDT (watchdog timer) can be used both during the boot process and during normal system operation.
•
During the boot process – If the operating system fails to boot in the time interval set in the BIOS, the
system will reset.
Enable the WDT in the Boot Settings menu of BIOS Setup Utility. Set the WDT for a time-out interval
in seconds, between 1 and 255, in one second increments. Ensure you allow enough time for the
operating system (OS) to boot. The OS or application must tickle (reset) the WDT before the timer
expires. This can be done by accessing the hardware directly or through a BIOS call.
•
During System Operation – An application can set up the WDT hardware through a BIOS call, or by
accessing the hardware directly. Some ADLINK Board Support Packages provide an API to the WDT.
The application must tickle (reset) the WDT before the timer expires or the system will be reset. The
BIOS implements interrupt 15 function 0x0C3h to manipulate the WDT.
•
Watchdog Code examples – ADLINK has provided source code examples on the ReadyBoard 620
Support Software DVD illustrating how to control the WDT. The code examples can be easily copied to
your development environment to compile and test the examples, or make any desired changes before
compiling. Refer to the WDT Readme file in the Miscellaneous Source Code Examples on the
ReadyBoard 620 Support Software DVD.
RB620_hotcable_b
Standard DB9 Serial
Cable Connector (Female)
Rear View
5 4 3 2 1
9 8 7 6