Motorola MVME177 manual Software Initialization, Multi-MPU Programming Considerations

3

Operating Instructions

8.Port commands to the 82596CA must be written as two 16-bit writes: upper word first and lower word second.

9.The CD2401 appears repeatedly from $FFF45200 to $FFF45FFF on the MVME177. If the local bus timer is enabled, the access times out and terminates by a TEA signal.

Software Initialization

Most functions that have been enabled with switches or jumpers on other modules are enabled by setting control registers on the MVME177. At power up or reset, the EPROMs that contain the 177Bug debugging package set up the default values of many of these registers.

Specific programming details may be determined by study of the M68060 Microprocessor User's Manual. You can also check the details of all the MVME177 onboard registers as given in the Single Board Computers Programmer's Reference Guide.

Multi-MPU Programming Considerations

Good programming practice dictates that only one MPU at a time has control of the MVME177 control registers.

Of particular note are:

❏Registers that modify the address map

❏Registers that require two cycles to access

❏VMEbus interrupt request registers

Local Reset Operation

Local reset (LRST) is a subset of system reset (SRST). Local reset can be generated five ways:

❏Expiration of the watchdog timer

3-8