Personal Computer User Manual

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PPCBug Firmware
3
For example, if a breakpoint has been specified, then control returns to the
debugger when the breakpoint is encountered during execution of the user
program. Alternately, the user program could return to the debugger by
means of the System Call Handler routine RETURN (described in the
PPCBug Firmware Package User’s Manual). For more about this, refer to
the GD, GO, and GT command descriptions in the PPCBug Firmware
Package User’s Manual, listed in Appendix C, Related Documentation .
A debugger command is made up of the following parts:
The command name, either uppercase or lowercase (for example,
MD or md)
Any required arguments, as specified by command
At least one space before the first argument. Precede all other
arguments with either a space or comma.
One or more options. Precede an option or a string of options with
a semicolon (;). If no option is entered, the command’s default
option conditions are used.
Hardware and Firmware Initialization
The debugger performs the hardware and firmware initialization process.
This process occurs each time the MVME5100 is reset or powered up. The
steps listed below are a high-level outline; be aware that not all of the
detailed steps are listed.
1. Sets MPU.MSR to known value.
2. Invalidates the MPU's data/instruction caches.
3. Clears all segment registers of the MPU.
4. Clears all block address translation registers of the MPU.
5. Initializes the MPU-bus-to-PCI-bus bridge device.
6. Initializes the PCI-bus-to-ISA-bus bridge device.
7. Calculates the external bus clock speed of the MPU.