Measuring data's high-speed transferring on PCI bus between DSP and POWERPC

Abstract

In many high-speed, real-time opto-electronic measurement systems, data's transferring is one of the main difficulties between the embedded processors. In this paper, a way of communication based on Peripheral Component Interconnect (PCI) bus is discussed between a POWERPC (POWERPC440GX) and DSP (TMS320DM642). By using the DSP'S enhanced direct-memory access (EDMA) controller, the data can be transferred in burst accesses mode in which the speed is very high. Since the EDMA controller of DM642 can access any portion of a block of internal data memory while the CPU is simultaneously accessing any portion of the other blocks, the transferring does not affect DSP's processing. The transfer mode is master write which is initiated under DSP control via the DSP register. With CPU 600MHz, 32bit 66M PCI of DM642 and 32 or 64-bit 66M PCI of POWERPC440GX, the PCI's peak transferring speed is up to 210MB/s which completely meets the system's real-time need. And this method is low cost comparing to other methods because the DSP's own PCI port is used. So this method can be widely used in data transferring and processing in high-speed, real-time opto-electronic measurement systems.