Motorola CPCI-6020 manual Harrier Xport Resources, Harrier B Memory Bus, 3 RAM500 Memory Mezzanine

Harrier B Memory Bus Functional Description

4.7.2Harrier B Memory Bus

Harrier B memory bus is also routed to a RAM500 compatible connector and has capabilities and characteristics identical to the Harrier A memory bus. The ECC protected memory banks on this memory bus appear as Banks C and E to Harrier B.

4.7.3RAM500 Memory Mezzanine

Each RAM500 mezzanine carries nine SDRAM parts in a x8 configuration, a buffer for certain control signals and a single +3.3 V, 256 x 8, SPD serial ROM. Each lower RAM500 attached to the host board has its SPD addressable at $AA from the Harrier to which it is attached, the upper at $AC.

The following are the expansion mezzanine size options for a single board. Boards of any size can be stacked.

Table 4-3 Expansion SDRAM Memory Mezzanine Size Options

SDRAM Memory		Device Organization	Number	Number of
Size (Banks)	Device Size	(depth x width-in-bits)	of Banks	Devices
32 MB	64 megabit	4 MB X 16	1	5
64 MB	64 megabit	8 MB X 8	1	9
128 MB	128 megabit	16 MB X 8	1	9
256 MB	256 megabit	32 MB X 8	1	9
512 MB	512 megabit	64 MB X 8	1	9

4.8Harrier Xport Resources

The Xport is a bridge that interfaces the 60x bus to an expansion bus named Xport Bus. Each of the two Harriers on CPCI-6020 has a separate Xport Bus. The Xport Bus is the set of signals Harrier uses to control devices that have a simple, static RAM style interface. Such devices include flash, NVRAM, RTC and external registers. A 60x bus slave and an Xport Bus master constitute the most significant blocks that make up Xport within Harrier. The 60x bus slave has four address response ranges. The Xport Bus master has four corresponding chip selects. An address range with its corresponding chip select is referred to as a channel (0 through 3). Each channel employs a combination of control registers and input signal pins to configure its address range and attributes. Refer to the Harrier Engineering Specification for additional details.

CPCI-6020 CompactPCI Single Board Computer Installation and Use (6806800A51C) 91