Chapter 3
Hardware
34
Reference Manual
CoreModule 720
Serial Console
The CoreModule 720 BIOS supports the serial console (or console redirection) feature. This I/O function is
ANSI-compatible with a serial terminal or with 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 entering the serial console settings in the BIOS Setup Utility
and connecting the appropriate serial cable (a standard null modem serial cable or “Hot Cable”) between one
of the serial ports (COM0) and the serial terminal or a PC with communications software.
Hot (Serial) Cable
To convert a standard serial cable to a “Hot Cable”, short together the RTS (7) and RI (9) pins on the serial
port DB9 connector as shown in
Figure 3-2
.
Figure 3-2. Serial Console Jumper
Watchdog Timer
The Watchdog Timer (WDT) restarts the system if a mishap occurs, ensuring proper start up after the
interruption. Possible problems include failure to boot properly, the application software’s loss of control,
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 using
Watchdog Timer
of the Boot menu in BIOS Setup. Set the WDT for a time-out
interval in seconds, between 0 and 600, in one-second increments in the Boot Configuration screen.
Ensure you allow enough time for the boot process to complete and for the OS to boot. The OS or
application must tickle the WDT as soon as it comes up. 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 interface to
the WDT. The application must tickle the WDT in the time set when the WDT is initialized or the
system will be reset. You can use a BIOS call to tickle the WDT or access the hardware directly.
•
Watchdog Code examples – ADLINK has provided source code examples on the CoreModule 720
Support Software QuickDrive 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 on the CoreModule 720 Support Software
QuickDrive.
CM720_HotCable
Standard DB9 Serial
Port Connector (Female)
Rear View
5
4
3
2
1
9
8
7
6