Motorola MVME2400 Series Wartungshandbuch PDF herunterladen (Seite 95)

Functional Description

http://www.mcg.mot.com/literature 2-37

Notes 1. “1000” is the default setting.

2. Parking disabled is a test mode only and should not be

used, since no one will drive the PCI bus when in idle state.

3. All other combinations in the PRK setting not specified in

the table are invalid and should not be used.

A special function is added to the PCI arbiter to hold the grant asserted

through a lock cycle. When the “POL” bit in the PCI arbiter control

will be held asserted until the lock cycle is complete. If this bit is clear, the

arbiter does not distinguish between lock and non-lock cycle.

Endian Conversion

The PHB supports both Big- and Little-Endian data formats. Since the PCI

bus is inherently Little-Endian, conversion is necessary if all PPC devices

are configured for Big-Endian operation. The PHB may be programmed to

perform the Endian conversion described below.

When PPC Devices are Big-Endian

When all PPC devices are operating in Big-Endian mode, all data to/from

the PCI bus must be swapped such that the PCI bus looks big endian from

the PPC bus’s perspective. This association is true regardless of whether

the transaction originates on the PCI bus or the PPC bus. This is shown in

Figure 2-7.

1000

Park on HAWK

1111

Parking disabled

Table 2-12. Arbitration Setting

PRK setting Function

1 2 ... 90 91 92 93 94 95 96 97 98 99 100 ... 353 354

Keine Kommentare

Motorola MVME2400 Series Wartungshandbuch Seite 95