Emerson MVME147 manual TARGET Sequence Custom Packet

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CUSTOM SCSI PACKETS

WORD $16: The interrupt level must be no-zero because TARGET role support is not used in non-interrupt mode. (If TARGET role support were done in polled mode, nothing else would be able to run on the MVME147 other than the TARGET firmware because the microprocessor would poll for a selection as a TARGET.) The vector number is used to provide the return path to you. (You take over that vector and point it to your service routine.)

IMPLEMENTATION NOTE: It is highly recommended that you assign a unique return vector for each enabled TARGET logical unit in order to keep the service of each LUN separate and independent from the other LUNs.

WORD $18: Not used by the firmware for the TARGET enable call.

WORD $1A: Not used by the firmware for the TARGET enable call.

TARGET Sequence Custom Packet

The TARGET sequence custom packet is shown in the following table.

Even Byte \

Odd Byte \

	FC		B8		74		30
+$00		Controller LUN				Device LUN
+$02		Status Byte 0				Status Byte 1 (Note 1)
+$04				Script Pointer (MSW)
+$06				Script Pointer (LSW)
+$08		Command Table Pointer (MSW) (Note 2)
+$0A		Command Table Pointer (LSW) (Note 2)
+$0C		0		0		0		0
+$0E		Flag = 8		0		0		0
+$10		0		0		0		0
+$12		0		0		0		0
+$14		0		0		Function Code (1C)
+$16		Interrupt Level				Vector Number
+$18		Status Byte 2				Status Byte 3 (Note 1)

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