Functional Description

 

 

 

 

 

 

Table 2-5. PCI Master Command Codes (Continued)

 

 

 

 

 

 

Entity Addressed

MPC

TBST

MEM

C/BE

PCI Command

Transfer Type

 

 

 

 

 

 

 

 

 

 

 

-- Unsupported --

 

 

1000

Reserved

 

 

 

 

 

-- Unsupported --

 

 

1001

Reserved

 

 

 

 

 

 

CONADD/CONDAT

Read

x

x

1010

Configuration Read

 

 

 

 

 

 

CONADD/CONDAT

Write

x

x

1011

Configuration Write

 

 

 

 

 

 

-- Unsupported --

 

 

1100

Memory Read Multiple

 

 

 

 

 

-- Unsupported --

 

 

1101

Dual Address Cycle

 

 

 

 

 

 

MPC Mapped PCI Space

Read

0

1

1110

Memory Read Line

 

 

 

 

 

 

-- Unsupported --

 

 

1111

Memory Write and

 

 

 

 

 

Invalidate

 

 

 

 

 

 

Addressing

The PCI master will generate all memory transactions using the linear incrementing addressing mode.

Combining, Merging, and Collapsing

The PCI master does not participate in any of these protocols.

Master Initiated Termination

The PCI master can handle any defined method of target retry, target disconnect, or target abort. If the target responds with a retry, the PCI master will wait for the required two clock periods and attempt the transaction again. The attempts will continue indefinitely until the transaction either completes, or is aborted by the target, or is aborted due to a Raven-detected bridge lock. The same happens if the target responds with a disconnect and there is still data to be transferred.

If the PCI master detects a target abort during a read, any untransferred read data will be filled with 1s. If the PCI master detects a target abort during a write, any untransferred portions of data will be dropped. The same rule applies if the PCI master generates a Master Abort cycle.

2

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Motorola MVME2300 Series manual Combining, Merging, and Collapsing, Master Initiated Termination