Host signal processing modem using a software simulation of a UART
US5787305A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 25, 1995 |
| Grant date | Jul 28, 1998 |
| Priority date | — |
| Expiry date | Apr 25, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/105
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A computer system includes a software UART emulation and uses standard operating system protocols to minimized the chance of I/O conflicts between a serial device having a UART and a non-standard serial device which communicates through the UART emulation. A COM driver which can replace a standard COM driver in an operating environment such as provided by Microsoft WINDOWS.TM. contains the UART emulation. The COM driver can also include a software modem that is accessed through the UART emulation in the same manner as a modem having a hardware UART. The COM driver also sets the device address of the non-standard device on an ISA bus by determining the device addresses of COM port I/O slots used by UARTs, sending a predetermined pattern on the ISA bus to indicate a device address is to come, and then sending a value indicating a device address not used by the UARTs. The pattern has a length sufficient to make inadvertent generation of the pattern unlikely. The non-standard device recognizes the predetermined pattern and selects a device address according to the value from the COM driver.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.