Chapter 8: PCI/G-Bus Bridge
TX7901 User’s Manual (Rev. 6.30T – Nov, 2001)
8-25
Bit(s)
Field
R/W
Description
12
e[1]
R/W
Enable for g2pWindow[1]. Cleared during reset. (0)
11
–
R/O
Reserved (0)
10:8
type[1]
R/W
Assigned to PCI C/BE[3:1]* during the PCI address phase through
g2pWindow[1]. Cleared during reset. (0)
7:5
–
R/O
Reserved. Read back as “0”. (0)
4
e[0]
R/W
Enable for g2pWindow[0]. Cleared during reset. (0)
3
–
R/W
Reserved
2:0
type[0]
R/W
Assigned to PCI C/BE[3:1]* during the PCI address phase through
g2pWindow[0]. Cleared during reset. (0)
* C/BE[0] is defined as 0: Read, 1: Write.
Note: Table 8-3 shows the g2p transactions supported by the PGB. In order to perform a
particular g2p transaction (shown in Table 8-3), set the “type” field in this register to
the corresponding C/BE#[3:1]. It is also important to note however that only a Read
is allowed when the “type” field is set to 3’b110, and a Write would cause a Dual
Address Cycle to be initiated. The PGB does not support Dual Address Cycles,
however. Furthermore, the cache configuration over the entire system should be
given careful consideration before using cache coherency commands where the type
field is 3b111.
8.3.2.2.5 Ia Address Register (Ia)
This register holds the addresses of failing G-Bus Master writes or the addresses of
transactions that cause WER errors (Window Crossover Errors). G-Bus Read access to this
register is allowed using the G-Bus single cycle mode. The fields of this register are detailed
below and in Table 8-12.
63
32
Ia [63:32]
32
31
3
2
0
Ia [31:3]
0
29
3
Table 8-12 IA Address Register Field Definitions
Bits
Field
R/W
Description
63:3
Ia
R/W
Address [63:0] for failing transaction. (0)
2:0
–
R/O
Reserved (0)
Summary of Contents for TMPR7901
Page 1: ...TX System RISC TX79 Family TMPR7901 Symmetric 2 way superscalar 64 bit CPU ...
Page 14: ...Handling Precautions ...
Page 15: ......
Page 17: ...1 Using Toshiba Semiconductors Safely 1 2 ...
Page 41: ...4 Precautions and Usage Considerations 4 2 ...
Page 42: ...TX7901 User s Manual Rev 6 30T November 2001 DOCUMENT NUMBER M 99 00004 07 ...
Page 43: ......
Page 259: ...Chapter 13 Removed TX7901 User s Manual Rev 6 30T Nov 2001 13 1 13 Removed ...
Page 260: ...Chapter 13 Removed TX7901 User s Manual Rev 6 30T Nov 2001 13 2 ...