Chapter 8: PCI/G-Bus Bridge
TX7901 User’s Manual (Rev. 6.30T – Nov, 2001)
8-32
8.6 Architecture
8.6.1 Major Internal Modules
This section identifies the main blocks comprising the PCI core. These blocks are listed
below and shown in Figure 8-12. Each core provides eight-location dual-port FIFOs to buffer
all data paths between the G-Bus and the PCI bus.
Master Write FIFO
Stores data from the G-Bus for Master Write cycles. Dual-
ported, 16 x 64b.
Target Read FIFO
Stores data from the G-Bus for Target Read cycles. Dual-
ported, 16 x 64b.
Multiplexer Registers
Used by the core to pre-load data from the G-Bus prior to
the PCI transfer. The multiplexer registers reduce data
transmission latency by storing pre-fetched data.
Output Multiplexer
Multiplexes addresses and data to the output registers.
Output Registers
Drive the PCI I/O buffers with addresses and data.
PCI ADOUT Register
Registers data and addresses from the PCI bus.
Master Read FIFO
Stores data from the PCI bus for Master Read cycles.
Dual-ported, 16 x 64b.
Target Write FIFO
Stores data from the PCI bus for Target Write cycles. Dual-
ported, 16 x 64b.
Master State Machine
Controls Master transfers, which are initiated by the G-Bus.
Target State Machine
Monitors Target transfers directed to the G-Bus by other
devices on the PCI bus.
Parity
Generates and checks parity on incoming and outgoing
addresses and data.
Command Decode
Decodes incoming commands from the PCI bus.
Address Compare
Compares incoming addresses with the base address
register’s contents.
Configuration Registers
Stores configuration information.
PCI Bus Registers
Used for Address translation.
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 ...
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