Chapter 10 PCI Controller
10-95
Bits Mnemonic Field
Name
Description
7 CHNEN
Chain
Enable
Chain Enable (Initial value: 0) (Read Only)
When the current data transfer is complete, this field reads the next data command
Descriptor from the address indicated by the PDMAC Chain Address Register then
indicates whether to continue the transfer or not.
This bit is only set to “1” when either a CPU Write process or a Descriptor Read
process sets a value other than “0” in the PDMAC Chain Address Register.
This bit is cleared to “0” if either the Channel Reset bit is set, or “0” is set in the
PDMAC Chain Address Register by a CPU Write or a Descriptor Read process.
1: Reads the next data command Descriptor.
0: Does not read the next data command Descriptor.
6
XFRACT
Transfer Active
Transfer Active (Initial value: 0, R/W)
Specifies whether to perform DMA transfer or not.
Setting this bit after setting the appropriate value in the register group initiates DMA
data transfer.
This bit is not set if the PDMAC Count Register value is “0” and the Chain Enable bit
is cleared when “1” is written to this bit.
Even when a value other than “0” is written to the Chain Address Register, “1” is set to
this bit and DMA transfer automatically starts.
Data transfer will be stopped after a short delay if this bit is cleared while the data
transfer is in progress.
This bit is automatically cleared to “0” either when data transfer ends normally or is
stopped by an error.
1: Perform data transfer.
0: Do not perform data transfer.
5:4
⎯
Reserved
⎯
3:2
XFRMODE
Transfer Mode
Transfer Size (Initial value: 0, R/W)
Specifies the transfer type (see detailed description in 0).
00: 1 DWORD (32-bit) with no overlap of G-Bus and PCI operation.
01: up to 16 DWORDs with no overlap of G-Bus and PCI operation.
10: Reserved
11: Reserved
1
XFRDIRC
Transfer Direction Transfer Direction (Initial value: 0, R/W)
Specifies the DMA data transfer direction.
1: Transfers data from the G-Bus to the PCI Bus.
0: Transfers data from the PCI Bus to the G-Bus.
0 CHRST
Channel
Reset
Channel
Reset (Initial value: 1, R/W)
Resets the DMA channel.
This bit must be cleared by the software in advance so the channel can start the data
transfer.
1: All logic and State Machines are reset.
0: The channel becomes valid.
Figure 10.4.65 PDMAC Configuration Register (2/2)
Summary of Contents for TMPR4925
Page 1: ...64 Bit TX System RISC TX49 Family TMPR4925 Rev 3 0 ...
Page 4: ......
Page 15: ...Handling Precautions ...
Page 16: ......
Page 18: ...1 Using Toshiba Semiconductors Safely 1 2 ...
Page 40: ...3 General Safety Precautions and Usage Considerations 3 18 ...
Page 42: ...4 Precautions and Usage Considerations 4 2 ...
Page 43: ...TMPR4925 ...
Page 44: ......
Page 54: ...Chapter 1 Features 1 8 ...
Page 58: ...Chapter 2 Block Diagram 2 4 ...
Page 88: ...Chapter 4 Address Mapping 4 12 ...
Page 226: ...Chapter 8 DMA Controller 8 58 ...
Page 260: ...Chapter 9 SDRAM Controller 9 34 ...
Page 480: ...Chapter 15 Interrupt Controller 15 32 ...
Page 554: ...Chapter 19 Real Time Clock RTC 19 8 ...
Page 555: ...Chapter 20 Removed 20 1 20 Removed ...
Page 556: ...Chapter 20 Removed 20 2 ...
Page 564: ...Chapter 21 Extended EJTAG Interface 21 8 ...
Page 580: ...Chapter 22 Electrical Characteristics 22 16 ...
Page 588: ...Chapter 24 Usage Notes 24 2 ...