Motorola MVME1X7P manual VMEbus Interface and VMEchip2, VMEchip2 General-Purpose I/O

Models: MVME1X7P

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Programming Issues

VMEbus Interface and VMEchip2

The local-bus-to-VMEbus interface and the VMEbus-to-local-bus interface are provided by the VMEchip2 ASIC. The VMEchip2 can also provide the VMEbus system controller functions. Refer to the VMEchip2 description in Chapter 2 for detailed programming information.

VMEchip2 General-Purpose I/O

The MVME1X7P single-board computers, both MVME167P and MVME177P, follow the previous MVME177 in their routing of GPIO signals:

GPIO1 controls Flash memory write protection.

GPIO3 selects between shared EPROM/Flash mode or Flash-only mode.

GPIO2 controls whether the upper or lower Flash addresses are used in shared EPROM/Flash mode.

GPIO0’s function as +12V power status signal is unchanged.

Petra/VMEchip2 Redundant Logic

In support of possible future configurations in which the MVME1X7P might be offered as a single-board computer without the VMEbus interface, certain logic in the VMEchip2 has been duplicated in the Petra chip. Table 1-2shows the location of the overlapping logic. As long as the VMEchip2 ASIC is present, the redundant logic is inhibited in the Petra chip.

Note that the ABORT switch logic in the VMEchip2 is not used. Likewise unused are the GPI inputs to the VMEchip2, which are located at $FFF40088 bits 7-0. Instead, the ABORT switch interrupt is integrated into the Petra ASIC at location $FFF42043. The GPI inputs are integrated into the Petra ASIC at location $FFF4202C bits 23-16.

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Motorola MVME1X7P manual VMEbus Interface and VMEchip2, VMEchip2 General-Purpose I/O, Petra/VMEchip2 Redundant Logic