Motorola CPCI-6020 manual ECC Memory Bus Resources, Debug Connector, PPC Bus Arbitration

Functional Description Debug Connector

Except where noted, Harrier A and Harrier B have the same default power-up setting.

4.6.3Debug Connector

One 190-pin Mictor connector with center row of power and ground pins is used to provide access to the processor bus and some miscellaneous signals. When the CPCI-6020 is populated with an MPC7410 processor this bus is not tolerant of +3.3 V or +5 V signals. Boards attached to this connector should not drive or pull signals up to intolerable levels.

4.6.4PPC Bus Arbitration

The Harrier ASIC contains arbiters for the PPC Bus and the PCI Bus. The Harrier A PPC arbiter is used to arbitrate between the processor, the Harrier A and the Harrier B PPC Bus masters for ownership of the PPC Bus. The processor is connected to the Harrier A arbiter CPU0_REQ/CPU0_GNT signal pair (XARB3/XARB0) and Harrier B is connected to the Harrier A arbiter EXTL_REQ/EXTL_GNT signal pair (XARB5/XARB2). For more information on PPC Bus arbitration refer to the CPCI-6020 CompactPCI Single Board Computer Programmer’s Reference Guide and the Harrier Application Specific Integrated Circuit (ASIC) Programmer’s Reference Guide.

4.7ECC Memory Bus Resources

The CPCI-6020 supports 2 GB of memory via four RAM500 mezzanine modules populated in the two memory connectors J7 and J28. There is no onboard memory. The ECC protected memory mezzanines are distributed as separate sets, one attached to each Harrier. The CPCI- 6020 supports a total of 1 GB using currently available 256 MB SDRAMs, (evenly divided between the two Harriers) and supports 2 GB when 512 MB SDRAMs become available.

4.7.1Harrier A Memory Bus

Harrier A memory bus is routed to a connector on which a RAM500 mezzanine may be mounted. The RAM500 mezzanine is capable of stacking so a total of two mezzanines may be attached to the Harrier A memory bus. The mezzanines appear as Banks C and E to the Harrier. Each mezzanine has a storage capacity of 256 MB of ECC protected memory using available 256 megabit SDRAMs, and a capacity of 512 MB when 512 megabit SDRAMs are available.

The I2C SPD serial ROMs on these mezzanines are connected to Harrier A’s I2C port 0.

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