Host signal processing modem using a software circular buffer in system memory and direct transfers of samples to maintain a communication signal
US6112266A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 22, 1998 |
| Grant date | Aug 29, 2000 |
| Priority date | — |
| Expiry date | Jan 22, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L69/40
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An HSP communication system includes a host computer which executes a software portion of an HSP modem and a device containing a digital-to-analog converter (DAC). In response to interrupts, the host executes an update routine that generates and writes samples to a software circular buffer in memory of the host computer. The samples represent amplitudes of an analog signal complying with a desired communication protocol. A direct transfer moves samples from the software circular buffer to a hardware circular buffer the device, and the DAC converts the samples from the hardware circular buffer into an analog communication signal. In an exemplary embodiment, the hardware portion is coupled to a PCI bus in the host computer, and direct transfers are according to the PCI bus master protocol. In environments such as multi-tasking systems, the host may skip interrupts or otherwise not provide new samples when required. In this case, the direct transfers transfer old samples, and the DAC reuses samples from the software circular buffer to generate a maintenance signal. If direct transfers are delayed, the DAC can reuses samples from the hardware circular buffer to generate the maintenance…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.