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IA8237
Advanced Information Sheet
Programmable DMA Controller
The IA8237 is a programmable direct memory access (DMA) mega-function designed to be
functionally equivalent to the Intel 8237A and Harris 82C37A devices. The A8237 controls data
transfers between memory and peripherals, memory-to-memory transfers, and block memory
initialization. Four independently programmable channels are available, and requests may be
generated via hardware or software.
A block diagram is shown in Figure 1.
Functional Block Diagram
Figure 1
A0 : A3
DECREMENTOR
INC/DECREMENTOR
EOP_n
RESET
CS_n
IO
BUFFER
TEMP WORD
COUNT REG
TEMP ADDRESS
REG
READY
CLK
16
TIMING
AND
CONTROL
AEN
A4 : A7
16
ADSTB
MEMR_n
MEMW_n
IOR_n
IOW_n
OUTPUT
BUFFER
READ BUFFER
READ WRITE BUFFER
BASE
WORD
CURRENT
CURRENT
BASE
ADDRESS
WORD
COUNT
ADDRESS
COUNT
COMMAND
CONTROL
WRITE
READ
BUFFER
BUFFER
DREQ0_n
DREQ3_n
:
DB0 : DB7
INTERNAL DATA
BUS
IO
BUFFER
COMMAND
MASK
PRIORITY
ENCODER
AND
ROTATING
PRIORITY
LOGIC
HDLA
HRQ_n
READ
DACK0
DACK3
:
STATUS
TEMPORARY
WRITE
MODE
REQUEST
Copyright ã 1999, InnovASIC Inc.
Customer Specific IC Solutions
INNOVASIC [ INNOVASIC, INC ]
