beautypg.com

Fly-by transfer by dma can be performed – FUJITSU MB91460 SERIES FR60 User Manual

Page 524

background image

508

Chapter 31 External Bus

1.Overview of the External Bus Interface

• Capable of setting timing values such as the CAS latency and RAS - CAS delay (SDRAM area)

• Capable of controlling the distributed/centralized auto - refresh, self - refresh, and other refresh timings

(SDRAM area)

Fly-by transfer by DMA can be performed.

• Transfer between memory and I/O can be performed in a single access operation.

• The memory wait cycle can be synchronized with the I/O wait cycle in fly-by transfer.

• The hold time can be secured by only extending transfer source access.

• Idle/recovery cycles specific to fly-by transfer can be set.

External bus arbitration using BRQ and BGRNT can be performed.

Pins that are not used by the external interface can be used as general-purpose I/O ports through
settings.