Chapter 10 PCI Controller
10-8
•
Special Cycle
This command issues specially cycles as the initiator only when in the Host mode. This
command issues special cycles on the PCI Bus when writing to the G2P Special Cycle Data
Register (G2PSPC). The written value is output as the special cycle data.
The TX4925 does not support special cycles as the target.
10.3.4 Initiator
Access
(G-Bus
→
PCI Bus address conversion)
During PCI initiator access, the G-Bus address of the Burst transaction issued by the G-Bus that was
converted into the PCI Bus address is used to issue a Burst transaction on the PCI Bus. 32-bit physical
address (G-Bus addresses) are used on the G-Bus. Also, 32-bit PCI Bus addresses are used on the PCI
Bus.
Three memory access windows and one I/O access window can be set in the G-Bus space (Figure
10.3.3). The size of each window is variable from 256 bytes to 512 Mbytes. When Burst transactions
are issued to these access windows on the G-Bus, then that G-Bus address is converted into a PCI Bus
address that is used to issue a Burst transaction to the PCI Bus as the initiator. PCI memory access is
issued when the access window is the memory access window. PCI I/O access is issued when the access
window is the I/O access window.
Figure 10.3.3 Initiator Access Memory Window
0x0000_0000
0xFFFF_FFFF
0x0000_0000
0x00_0000_0000
0xFFFF_FFFF
0xFFFF_FFFF
PCI I/O Space
G-Bus Space
PCI Memory Space
Memory Access Window
I/O Access Window
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 ...