4. DMA
117
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
4.2.6
Processor Bus Transfer Attributes
“DMA x Attributes Register” on page 317
controls the read and write transactions generated by
the DMA as a processor bus master.
The default transfer type generated by the processor bus master is shown in
The Global (PB_GBL_) and Cache Inhibit (PB_CI_) parameters are programmable for each DMA in
the
“DMA x Attributes Register” on page 317
. Assertion of PB_GBL_ during a processor bus master
transaction instructs all processors on the bus to snoop the transaction. Control of this parameter
enables the user to implement non-coherent accesses in specific areas of memory. Assertion of PB_CI_
prohibits external agents from caching the transaction.
DONE
R/
Write 1 to
clear
A status bit indicating if the DMA has been completed its Direct
mode or Linked-List mode.
Clear
P1_ERR_EN
R/W
Enables an interrupt if an error occurs on PCI-1.
Disabled
P2_ERR_EN
R/W
Enables an interrupt if an error occurs on PCI-2. Do not
program this bit if using the Single PCI PowerSpan II
.
Disabled
PB_ERR_EN
R/W
Enables an interrupt if an error occurs on the processor bus.
Disabled
STOP_EN
R/W
Enables an interrupt if the DMA has been stopped (STOP_REQ
bit was set).
Disabled
HALT_EN
R/W
Enables an interrupt if the DMA has been halted (HALT_REQ
bit was set).
Disabled
DONE_EN
R/W
Enables an interrupt if the DMA completes its Direct mode or
Linked-List mode.
Disabled
Table 28: Default PowerSpan II PB Master Transfer Type
PB Master Transfer
PB_TT[0:4]
60x Command
Writes
00010
Write with flush
Reads
01010
Read
Table 27: Programming Model for DMA General Control and Status Register
Bits
Type
Description
Default Setting