MCS9904

Please register MyASIX membership and then download the latest MCS9900/MCS9901/MCS9904/MCS9922 datasheet, reference schematic, PCB layout guide, etc. from ASIX Interface ICs Product web pages directly.

Yes, please deliver your own MCS99xx schematic and PCB layout files to ASIX's Support (support@asix.com.tw) for further review before making your own MCS99xx PCB board.

If you are a new PCI/PCIe product developer looking to get a PCI Vendor ID for your company, you can register a PCI Vendor ID from PCI-SIG (Peripheral Component Interconnect Special Interest Group). Please visit the PCI-SIG web site for details.

The utility can program the I2C EEPROM while it is in-circuit. There is no need to pre-program it and then place it on the PCB.

Cable length is one of the most discussed items in RS232 world. The standard has a clear answer; the maximum serial cable length is 50 feet, or the cable length equal to a capacitance of 2500 pF.

Please visit ASIX Driver Download web pages to download proper drivers for your MCS9900/MCS9901/MCS9904/MCS9922 target applications.

It is not possible to manually change IRQ setting of all PCIe devices in any operating systems because the IRQ used by the device is assigned by the PCIe system and cannot be changed. Usually the only way to change the IRQ of a PCIe device is to move it to a different PCIe slot. Each slot is usually assigned a different IRQ, although this is not always true. Each system may handle the assignment of IRQs differently.

MCS99xx is a PCI Express to multi-I/O controller so it does not support to remap the parallel/serial ports base address into legacy I/O address range. The limitation is inherent in PCI Express system architectures. On most of Windows/Linux systems, the legacy I/O address remapping feature is not required.
For some specific old parallel/serial devices, users might still need to support the legacy I/O address in order to work on their existing software under DOS. In this case, users can consider using ASIX PCI bridge I/O connectivity products to support this inquiry.

Only the MCS99xx DOS and Windows NT drivers have a mechanism to manually select the desired LPT Mode for MCS99xx Parallel port. The Windows systems are supposed to be able to auto-switch to a proper LPT mode for PCIe based parallel port devices. Unfortunately, this LPT mode automatic switching functionality does not work very well with PCIe based Parallel port devices on Windows systems. MCS99xx can support SPP and PS/2 Modes without any problems. The EPP and ECP modes supporting varies from machine to machine and depends on the Operating System being used. Both EPP and ECP modes require two banks of Standard/Extended registers to control the standard/enhanced functionality of MCS99xx Parallel port. The base address of 2nd bank Extended registers must be equal to "the base address of 1st bank Standard registers + 400h" to meet the IEEE-1284 standard specification. Unfortunately, the PCIe specification does not make any guarantees that two resource requests will have any specific relationship to each other. We request the two banks with the desired offset, but the system does not always honor those requests, and often returns the extended register bank at some entirely different address than what we requested. When this occurs, neither EPP nor ECP Mode will be workable. For this reason, some software (including Device Drivers for Printers etc.) will not work with MCS99xx PCIe based Parallel port.

Yes, the COM port number of MCS99xx can be changed to a desired number that is free and un-used by device/serial application. If you are using Windows systems, there is a control which will let you change the COM port number easily.
1. Go into the Device Manager.
2. Open the Properties page for the Port in question (under Ports COM & LPT).
3. In the "Port Settings" tab, click the "Advanced" button. On the screen that opens is the control to change the COM port number.

Yes, we can change the LPT port number by using a drop down list located in LPT Port Properties. To change the LPT port number, go to "LPT Port Properties => Port Setting => LPT Port Number". If there is no standard LPT port available on motherboard, MCS99xx LPT port will automatically enumerate as LPT1, otherwise it will enumerate as LPT3.

In DOS operating system, the serial mouse driver expects the standard IRQ to be present for serial port. The IRQ of MCS99xx serial ports, which is different from the standard serial port, is assigned by system BIOS and cannot be changed. Therefore, the serial mouse support is not possible under DOS for MCS99xx.