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Raven PCI Bridge ASIC

BUS

Bus Number.

Configuration Cycles: Identifies a targeted bus number. If written with all zeros, a Type 0 Configuration Cycle will be generated. If written with any value other than all 0s, then a Type 1 Configuration Cycle will be generated.

Special Cycles: Identifies a targeted bus number. If written with all 0s, a Special Cycle will be generated. If written with any value other than all 0s, then a Special Cycle translated into a Type 1 Configuration Cycle will be generated.

EN Enable.

Configuration Cycles: Writing a 1 to this bit enables

CONFIG_DATA to Configuration Cycle translation. If this bit is a 0, subsequent accesses to CONFIG_DATA will be passed though as I/O cycles.

Special Cycles: Writing a 1 to this bit enables CONFIG_DATA to

Special Cycle translation. If this bit is a 0, subsequent accesses to

CONFIG_DATA will be passed though as I/O cycles.

CONFIG_DATA Register

The description of the CONFIG_DATA register is also presented in three perspectives: from the PCI bus, from the MPC bus in big-endian mode, and from the MPC bus in little-lndian mode. Note that the view from the PCI bus is purely conceptual, since there is no way to access the CONFIG_DATA register from the PCI bus.

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Motorola MVME2300 Series manual Bus, EN Enable, Configdata Register