Emerson MVME147 manual Interface Rules for a Single Caller

Interface Rules for the SCSI Firmware

* RESTORE REGISTERS FOR SCSI ROUTINE

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*The driver must restore the registers the SCSI firmware has used.

*A3 is pointing to a list of the registers to restore.

*The following code is for 68010 or newer processor and could be more

*efficient if more advanced processor as 68020, 68030 is used.

* Entry: A3 = Pointer to register list of registers to

*restore.

*Exit: Back to caller.

RESTORE_REG:

MOVE.L #14,D0			Number of longwords to move
				= 15.
	ADDA.L	#60,A3		Start from bottom
of register
				list.
RSTRLOOP	MOVE.L	-(A3),-(SP)		Store on the stack
for MOVEM
				instruction.
	DBRA	D0,RSTRLOOP
	MOVEM.L (SP)+,D0-D7/A0-A6			Restore registers.
REST_OUT	RTS

END

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Interface Rules for a Single Caller

You can use the same rules as provided for multiple callers. By doing so, a second or third caller may later be added without the necessity of modifying the initial caller routine. By using the rules for multiple callers, a user also expects the firmware to do more work than would otherwise have to be done

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