Datasheet Summary
NEe Microputers, Inc.
NEe
JLPD8257 JLPD8257- 5
PROGRAMMABLE DMA CONTROLLER
DESCR IPTION
The !1PD8257-5 is a programmable four-channel Direct Memory Access (DMA) controller. It is designed to simplify high speed transfers between peripheral devices and memories. Upon a peripheral request, the !1PD8257-5 generates a sequential memory address, thus allowing the peripheral to read or write data directly to or from memory. Peripheral requests are prioritized within the !1PD8257-5 so that the system bus may be acquired by the generation of a single HOLD mand to the 8080A. DMA cycle counts are maintained for each of the four channels, and a control signal notifies the peripheral when the...