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Programming Issues

Battery-Backed-Up RAM and Clock

Although the M48T58-70 RAM and clock chip is an 8-bit device, the interface provided by the PCCchip2 supports 8-, 16-, and 32-bit accesses to the M48T58. No interrupts are generated by the clock. Refer to Chapter 3, PCCchip2 and to the M48T58 data sheet for detailed programming guidance and battery life information.

VMEbus Interface

The VMEbus interface is implemented with an ASIC called the

VMEchip2. The VMEchip2 includes:

Two tick timers

A watchdog timer

Programmable map decoders for the master and slave interfaces

A VMEbus to/from local bus DMA controller

A VMEbus to/from local bus non-DMA programmed access interface

A VMEbus interrupter, a VMEbus system controller, a VMEbus interrupt handler, and a VMEbus requester

Processor-to-VMEbus transfers can be D8, D16, or D32. VMEchip2 DMA transfers to the VMEbus, however, can be D16, D32, D16/BLT, D32/BLT, or D64/MBLT.

Refer to Chapter 2, VMEchip2 for detailed programming information.

I/O Interfaces

The MVME167P and MVME177P single-board computers provide onboard I/O for many system applications. The I/O functions include serial ports, parallel (printer) port, Ethernet transceiver interface, and SCSI mass storage interface.

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Motorola MVME1X7P manual Battery-Backed-Up RAM and Clock, VMEbus Interface, Interfaces