Specifications

DMA Controller (V40)
FUNCTIONAL DESCRIPTION
Figure 9-1 illustrates a block diagram of the DCU. The DCU is
divided into six major blocks for explanation purposes. Each of these
functional blocks is discussed below.
Internal Bus
Interface
A0-A19
D0-D15
CONTROL
BRQ
BAK
DRQ
DAK
Address Adjuster
Address Register
Current Address
Base Address
Current Count
Base Count
Count Adjuster
Initialization
Channel
Status
Mask
Device Control
Mode Control
Control Registers
Count Register
Figure 9–1. DCU Block Diagram.
9-4