Computer Hardware User Manual

PCI200 User Guide Texas Memory Systems, Inc. (8/6/01) C-2
3 ECHO RO Indicates the XP-15 has returned an ECHO packet
2 SPR RO Indicates the XP-15 has returned an SPR packet
1 DIAG RO Indicates the XP-15 has returned a diagnostic packet
0 STAT RO Indicates the XP-15 has returned a status packet
Low PCI SN command address register (32 bits, R/W)
Bit # Name Type Description
31-3 NA R/W This register is used to establish the low 32-bits of the PCI
address for SN commands to the XP-15. This register consists
of the bottom 32-bits of a 32-bit counter with the low-order
three bits hardwired to zeroes. Transfers must begin on a
Double DWORD (64-bit) boundary.
2-0 Reserved RO These bits are reserved (must be written with zeroes).
High PCI SN command address register (32 bits, R/W)
Bit # Name Type Description
63-32 NA R/W Upper bits of this register are not used.
Low PCI SN response address register (32 bits, R/W)
Bit # Name Type Description
31-3 NA R/W This register is used to establish the low 32-bits of the PCI
address for SN responses from the XP-15. This register
consists of the bottom 32-bits of a 32-bit counter with the low-
order three bits hardwired to zeroes. Transfers must begin
on a Double DWORD (64-bit) boundary.
2-0 Reserved RO These bits are reserved (must be written with zeroes).
High PCI SN response address register (32 bits, R/W)
Bit # Name Type Description
63-32 NA R/W Upper bits of this register are not used.