Claims
- 1. A data processing device, comprising:a central processing unit (CPU) operable to execute software instructions stored in a program memory circuit connected to the central processing unit; a data memory circuit operable to store data to be processed by the processing device; and a direct memory access (DMA) controller having a plurality of DMA channels, wherein each DMA channel has associated programmable read address circuitry and programmable write address circuitry, each DMA channel operable to transfer data from or to the data memory circuit, the DMA controller comprising:a FIFO buffer connected to a data bus to receive a plurality of data elements received in response to the read address circuitry associated with a selected one of the plurality of DMA channels, the FIFO buffer operable to hold a portion of the plurality of data elements until the portion of the plurality of data elements is written in response to the write address circuitry of the selected one of the plurality of DMA channels; and wherein the FIFO buffer is operable to be selectively associated with any one of the plurality of DMA channels, such that non-selected ones of the plurality of DMA channels are operable to transfer data from or to the data memory without use of the FIFO.
- 2. The data processing device of claim 1, wherein a first channel of the plurality of DMA channels is selected to be associated with the FIFO in response to a first channel priority of the first channel being higher than a channel priority of any other of the plurality of channels.
- 3. The data processing device of claim 2, wherein a second channel of the plurality of DMA channels is selected to be associated with the FIFO in response to a second channel priority of the second channel becoming higher than the first channel priority while the first channel is transferring data, such that the first channel is then operable to transfer data from or to the data memory without use of the FIFO.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of patent application Ser. No. 09/054,833, filed Apr. 3, 1998, which claims priority under 35 USC §119(e)(1) of Provisional Application No. 60/053,076, filed Jul. 9, 1997 now U.S. Pat. No. 6,145,027.
This application is related to co-assigned application Ser. No. 09/012,813 Ser. No. 08/974,742 Ser. No. 09/055,011 and U.S. Pat. No. 6,058,474 filed contemporaneously herewith and incorporated herein by reference.
US Referenced Citations (11)
Provisional Applications (1)
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Number |
Date |
Country |
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60/053076 |
Jul 1997 |
US |