System Features

System Resources

The table below lists the default system resources utilized by the circuits on Poseidon.

Device Address ISA IRQ ISA DMA
Serial Port COM1 I/O 0x3F8 – 0x3FF 4 –
Serial Port COM2 I/O 0x2F8 – 0x2FF 3 –
Serial Port COM3 I/O 0x3E8 – 0x3EF 7 –
Serial Port COM4 I/O 0x2E8 – 0x2EF 10 –
IDE Controller I/O 0x1F0 – 0x1F7 14 –
A/D Circuit (when applicable) I/O 0x140 – 0x380 5 –
Serial Port / FPGA Control I/O 0xA50-0xA5F – –
Ethernet OS-dependent OS-dependent –
USB OS-dependent OS-dependent –
Sound OS-dependent OS-dependent –
Video OS-dependent OS-dependent –

Most of these resources are configurable and, in many cases, the Operating System alters these settings. The main devices that are subject to this dynamic configuration are on-board Ethernet, sound, video, USB, and any PC/104-Plus cards that are in the system. These settings may also vary depending on what other devices are present in the system. For example, adding a PC/104-Plus card may change the on-board Ethernet resources.

The serial port settings for COM3 and COM4 are jumper selectable, whereas the settings for COM1 and COM2 are entirely software-configured in the BIOS.

Console Redirection to a Serial Port

In many applications without a local display and keyboard, it may be necessary to obtain keyboard and monitor access to the CPU for configuration, file transfer, or other operations. Poseidon supports this operation by enabling keyboard input and character output onto a serial port, referred to as console redirection. A serial port on another PC can be connected to the serial port on Poseidon with a null modem cable, and a terminal emulation program, such as HyperTerminal, can be used to establish the connection. The terminal program must be capable of transmitting special characters including F2 (some programs or configurations trap special characters).

The default Poseidon BIOS setting enables console redirection onto COM2 during power-on self-test (POST). Communication parameters are 115.2Kbaud, N, 8, 1. When the CPU is powered up, the BIOS outputs POST information to COM2 and monitors the port it for any keyboard activity. You can enter the BIOS by pressing F2 during this time interval. In the default configuration, console redirection is disabled after POST is finished and the CPU boots.

There are three possible configurations for console redirection:

  • POST-only (default)

  • Always On

  • Disabled

    • To modify the console redirection settings,

    1. Enter the BIOS

    2. Select the Advanced menu

    3. Select Console Redirection.

    4. In Com Port Address, select Disabled to disable the function, On-board COM A for COM1, or On-board COM B for COM2 (default).
      If you select Disabled, you will not be able to enter BIOS again during power-up through the serial port.

    To reenter BIOS when console redirection is disabled, you must either install a PC/104 video board and use a keyboard and terminal or erase the CMOS RAM, which will return the BIOS to its default settings. CMOS RAM may be erased by removing the jumper on the JP6 jumper block.

    Note: Before erasing CMOS RAM, write down any custom BIOS settings you have made.

    If you erase the CMOS RAM, the next time the CPU powers up COM2 returns to the default settings of 115.2Kbaud, N, 8, 1 and operates only during POST.

    If you selected COMA or COMB, continue with the configuration, as follows.

    1. For Console Type, select PC ANSI.

    2. You can modify the baud rate and flow control here if desired.

    3. At the bottom, for Continue C.R. after POST, select Off (default) to turn off after POST or select On to remain on always.

    4. Exit the BIOS and save your settings.

    Flash Memory

    Poseidon contains a 2Mbyte, 16-bit wide flash memory chip for storage of BIOS and other system configuration data.

    Backup Battery

    Poseidon contains an integrated RTC/CMOS RAM backup battery. This battery has a capacity of 120mAH and will last over three years in power-off state. There is also a connection points for alternative, external battery power on header CN8.

    The external battery should be 3-3.6V and should be able to provide a continuous supply with a nominal 2uA continuous current drain and a peak short-term drain of 1mA. An external battery is only recommended where concern for on-board CMOS settings and/or time accuracy make such redundancy worthwhile.

    The on-board battery is activated for the first time during initial factory configuration and test.

    System Reset

    Poseidon contains a chip to control system reset operation. Reset occurs under the following conditions.

  • User causes reset with a ground contact on the Reset input.

  • Input voltage drops below 4.75V.

  • Over-current condition on output power line .

    • The ISA Reset signal is an active high pulse with a 200ms duration. The PCI Reset is active low, with a typical pulse width duration of 200 msec.

    On-Board Video

    Using the the on-board VIA CX700 processor, Poseidon integrates all of the support needed for modern media. Refer to the VIA Technologies, Inc. documentation for CX700-series processors, listed in the Additional Information section of this document.