Motorola MVME1X7P VMEbus Memory Map, Interrupt Acknowledge Map, VMEbus Accesses to the Local Bus

Models: MVME1X7P

1 316
Download 316 pages 46.44 Kb
Page 72
Image 72

1

Programming Issues

15.The final byte of the area is reserved for a checksum (as defined in the Debugging Package User’s Manual for MVME167Bug and MVME177Bug, and the Debugging Package for Motorola 68K CISC CPUs User’s Manual) for security and data integrity of the configuration area of the NVRAM. This data is stored in hexadecimal format.

Interrupt Acknowledge Map

The local bus distinguishes interrupt acknowledge cycles from other cycles by placing the binary value %11 on TT1-TT0. It also specifies the level that is being acknowledged using TM2-TM0. The interrupt handler selects which device within that level is being acknowledged.

VMEbus Memory Map

This section describes the mapping of local resources as viewed by VMEbus masters. Default addresses for the slave, master, and GCSR address decoders are provided by the ENV command.

VMEbus Accesses to the Local Bus

The VMEchip2 includes a user-programmable map decoder for the VMEbus-to-local-bus interface. The map decoder allows you to program the starting and ending address and the modifiers to which the MVME1X7P responds.

VMEbus Short I/O Memory Map

The VMEchip2 includes a user-programmable map decoder for the GCSR. The GCSR map decoder allows you to program the starting address of the GCSR in the VMEbus short I/O space.

1-46

Computer Group Literature Center Web Site

Page 72
Image 72
Motorola MVME1X7P manual VMEbus Memory Map, Interrupt Acknowledge Map, VMEbus Accesses to the Local Bus