Emerson MVME147 User Manual
CUSTOM SCSI PACKETS
2-22
2
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.
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)