8-18
MPC8240 Integrated Processor User’s Manual
DMA Register Descriptions
The values in the PRC field are used as follows:
•
If PRC = 00 (PCI read), then all DMA reads from PCI use the PCI read command.
•
If PRC = 01 (PCI read line), then the PCI read line command is used if the PCLSR
(see Section 4.2.5, “PCI Cache Line Size—Offset 0x0C) is programmed for 32-byte
cache lines, and the current DMA transfer is for at least two 32-bit transactions.
Otherwise, PCI read commands are used.
•
If PRC = 10 (PCI read multiple), then the PCI read multiple command if used if the
PCLSR is programmed for 32-byte cache lines, the current DMA transfer is aligned
on a cache line address, and more than one full cache line of data is to be transferred.
Otherwise, if the current DMA transfer is for at least two 32-bit transactions (and
less than or equal to one cache line), then the read line command is used. If the
conditions for using the PCI read line command above are not met, then the PCI read
command is used.
8.7.2 DMA Status Registers (DSRs)
The DSRs report various DMA conditions during and after the DMA transfer. Writing a 1
to a set bit clears the bit. Software attempting to determine the source of interrupts should
always perform a logical AND function between the bits of the DSR and their
corresponding enable bits in the DMR and CDAR. Figure 8-5 shows the bits in the DSRs.
Figure 8-5. DMA Status Register (DSR)
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
00
0
31
8
7
6
5
4
3
2
1
0
Reserved
LME
PE
CB
EOSI
EOCAI
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 ...