器件名称:
A8237
功能描述:
PROGRAMMABLE DMA CONTROLLER
文件大小:
269.87KB 共22页
简 介:
a8237 Programmable DMA Controller Data Sheet April 1999, ver. 1.01 Features s s s s s s s a8237 MegaCore function implementing a programmable direct memory access (DMA) controller Optimized for FLEX architecture Provides four independent channels Offers static read/write or handshaking modes Includes direct bit set/reset capability Uses approximately 1,201 FLEX logic elements (LEs) Functionally based on the Intel 8237A and Harris 82C37A devices, except as noted in “Variations & Clarifications” on page 24 General Description The a8237 MegaCore function implements a programmable DMA controller, which controls memory-to-peripheral and memory-tomemory data transfers and provides block memory initialization capability. Four independently programmable channels are available in the a8237, and DMA requests can be made via hardware or software. Figure 1 shows the symbol for the a8237. Figure 1. a8237 Symbol A8237 clk hlda ncs neopin niorin niowin ready reset ain[3..0] dbin[7..0] dreq[3..0] adstb aen dben dmaenable hrq neopout niorout niowout nmemr nmemw aout[7..0] dack[3..0] dbout[7..0] Altera Corporation A-DS-A8237-01.01 5 a8237 Programmable DMA Controller Data Sheet Table 1 describes the input and output ports of the a8237 MegaCore function. Table 1. a8237 Ports (Part 1 of 2) Name clk hlda ncs neopin niorin niowin ready Type Input Input Input Input Input Input Input Polarity – High Low Low Low Low High Description Clock. Used to generate and synchronize a8237 oper……
