Chapter 8. DMA Controller
8-7
DMA Operation
8.3.3 DMA Operation Flow
Figure 8-2 shows a general flow diagram for the operation of the DMA controller on the
MPC8240.
Figure 8-2. DMA Controller General Flow
Save CDAR
Periodic mode
Timer Expires.
Restore CDAR
Chaining mode
Load the parameters
from memory into
the DMA registers
Load the contents of
NDAR into CDAR
Use the parameters
in the DMA registers
Read a line
*
of data
from memory (or PCI)
and decrement BCR
Write a line
*
of data
to memory (or PCI)
Direct mode
Done
Done
*
The first and/or last transfer will
be less than a line size transfer if
the initial address is not line
aligned and/or the byte count is
not an exact multiple of lines.
EOCA
BCR = 0
otherwise
Direct mode
otherwise
otherwise
EOTD = 1
otherwise
Periodic mode
EOSI
0
1
EOCAI
1
Summary of Contents for MPC8240
Page 1: ...MPC8240UM D Rev 1 1 2001 MPC8240 Integrated Processor User s Manual ...
Page 38: ...xviii MPC8240 Integrated Processor User s Manual TABLES Table Number Title Page Number ...
Page 48: ...xlviii MPC8240 Integrated Processor User s Manual Acronyms and Abbreviations ...
Page 312: ...6 94 MPC8240 Integrated Processor User s Manual ROM Flash Interface Operation ...
Page 348: ...7 36 MPC8240 Integrated Processor User s Manual PCI Host and Agent Modes ...
Page 372: ...8 24 MPC8240 Integrated Processor User s Manual DMA Register Descriptions ...
Page 394: ...9 22 MPC8240 Integrated Processor User s Manual I2O Interface ...
Page 412: ...10 18 MPC8240 Integrated Processor User s Manual Programming Guidelines ...
Page 454: ...12 14 MPC8240 Integrated Processor User s Manual Internal Arbitration ...
Page 466: ...13 12 MPC8240 Integrated Processor User s Manual Exception Latencies ...
Page 516: ...16 14 Watchpoint Trigger Applications ...
Page 538: ...B 16 MPC8240 Integrated Processor User s Manual Setting the Endian Mode of Operation ...
Page 546: ...C 8 MPC8240 Integrated Processor User s Manual ...
Page 640: ...INDEX Index 16 MPC8240 Integrated Processor User s Manual ...