ibm3206k0424 ETC-unknow, ibm3206k0424 Datasheet - Page 177

• Manufacturer Part Number: ibm3206k0424
• Description: Ibm Processor For Network Resources
• Manufacturer: ETC-unknow

Preliminary
4.3: GPDMA Control Register
Used to set options for DMA operations. See Note on Set/Clear Type Registers on page 93 for more details
on addressing.
Length
Type
Address
Power on Value
Restrictions
pnr25.chapt04.01
August 14, 2000
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
23-20
19-16
Bit(s)
15-9
31
30
29
28
27
26
25
24
Assume 64
Assume 32
Assume 64
Assume 32
Assume 64
Assume 32
Assume 64
Assume 32
PCI Transfer Threshold
Memory Transfer Threshold
DMA Transaction Timeout
Function
32 bits
Read/Write
XXXX 0118 and 1C
X’008800c7’
None
Assume 64-bit PCI Interface for Descriptor Transfers
Assume 32-bit PCI Interface for Descriptor Transfers
Assume 64-bit PCI Interface for Queue 2 Transfers
Assume 32-bit PCI Interface for Queue 2 Transfers
Assume 64-bit PCI Interface for Queue 1 Transfers
Assume 32-bit PCI Interface for Queue 1 Transfers
Assume 64-bit PCI Interface for Queue 0 Transfers
Assume 32-bit PCI Interface for Queue 0 Transfers 2
The value of these bits multiplied by eight determines the number of bytes that must be
ready to transfer before a DMA transfer is initiated on the PCI bus. This can be used to
tune the performance of the PCI bus. If the number of bytes left to transfer is less than
the threshold, the transfer will start when all remaining bytes are ready to be transferred.
The value of these bits multiplied by eight determine the number of bytes that must be
ready to transfer before a transfer is initiated on the internal memory bus. This can be
used to tune the performance of the memory subsystem.
These bits hold a value that is used to count the number of cycles that an unacknowl-
edged DMA cycle is in progress. If the count is reached, due to an internal chip hang
condition, the DMA is terminated. A value of ’0’ disables this function.
Description
IBM Processor for Network Resources
9
8
General Purpose DMA (GPDMA)
7
6
5
4
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IBM3206K0424
3
2
1
0