Motorola MVME187 Mpcr Status Codes, Multiprocessor Address Register Mpar, Mpcr Powerup Sequence

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Debugger General Information

MPCR Status Codes

The status codes stored in the MPCR are of two types:

❏Status returned (from 187Bug)

❏Command set by the bus master (job requested by some processor)

The status codes that may be returned from 187Bug are:

HEX	0	(HEX 00)	-- Wait. Initialization not yet complete.
ASCII	R	(HEX 52)	--	Ready. The Þrmware monitor is watching for a change.
ASCII	E	(HEX 45)	--	Code pointed to by the MPAR is executing.

The command code that may be set by the bus master is:

ASCII	G	(HEX 47)	--	Use Go Direct (GD) logic specifying the MPAR address.
ASCII	B	(HEX 42)	--	Recognize breakpoints using the Go (G) logic.

Multiprocessor Address Register (MPAR)

The Multiprocessor Address Register (MPAR), located in shared RAM location of $3004 offset from the base address the debugger loads it at, contains the second of two words used to control communication between processors. The MPAR contents specify the physical address (as viewed from the local processor) at which execution for this processor is to begin if the MPCR contains a G or B. The MPAR is organized as follows:

Base Address + $3004 * * * * (MPAR)

MPCR Powerup Sequence

1.At powerup, the debug monitor self-test routines initialize RAM, including the memory locations used for multi- processor support ($3000 through $3007).

2.The MPCR contains $00 at powerup, indicating that initialization is not yet complete.

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