Block Diagram; Layout Notes - Intel PXA27 Series Design Manual

DMA Controller Interface
5.5.1.2

Block Diagram

See Figure 5-2
chip using fly-by DMA transfers to SDRAM memory devices.
Figure 5-2. Companion Chip Using Fly-by DMA Transfer Interface
5.5.1.3

Layout Notes

Using fly-by DMA transfers, high-performance companion chips are directly connected to the data
bus of the SDRAM devices. All companion chips are restricted to transfers whose alignment and
length match those of the SDRAM devices.
II:5-4
for illustration showing how to interface the PXA27x processor to a companion
PXA27x Processor
Control
Signals
Flyby_DMA_
Request
DMA Memory
Controller Controller
DREQx DVALx
Companion Chip
SDCKE<1>
SDCLK<2:1>
nSDCS<3:0>
nSDRAS
nSDCAS
nWE
MA<24:10>
DQM<3:0>
MD<31:0>
®
Intel PXA27x Processor Family Design Guide
SDRAM
Memory
Devices
DMA_001_P2