
29
Data Device Corporation
www.ddc-web.com
BU-6174X/6184X/6186X
Rev. C
RT COMMAND ILLEGALIZATION
The Enhanced Mini-ACE provides an internal mechanism for RT
Command Word illegalizing. By means of a 256-word area in
shared RAM, the host processor may designate that any mes-
sage be illegalized, based on the command word T/R bit, sub-
address, and word count/mode code fields. The Enhanced Mini-
ACE illegalization scheme provides the maximum in flexibility,
allowing any subset of the 4096 possible combinations of broad-
cast/own address, T/R bit, subaddress, and word count/mode
code to be illegalized.
The address map of the Enhanced Mini-ACE's illegalizing table
is illustrated in TABLE 41.
TABLE 41. ILLEGALIZATION TABLE MEMORY MAP
3FC
3BE
3C2
381
33F
300
ADDRESS
Own Addr / Tx, SA 30. WC15-0
Own Addr / Rx, SA 31. MC15-0
Brdcst / Tx, SA 30. WC31-16
Own Addr / Tx, SA 1. WC15-0
Own Addr / Rx, SA 0. MC31-16
Brdcst / Rx, SA 31. MC31-16
Brdcst / Rx, SA 0. MC15-0
DESCRIPTION
3FD
3BF
37E
3C3
382
340
301
Own Addr / Tx, SA 30. WC31-16
Own Addr / Rx, SA 31. MC31-16
Brdcst / Tx, SA 31. MC15-0
Own Addr / Tx, SA 1. WC31-16
Own Addr / Rx, SA 1. WC15-0
Brdcst / Tx, SA 0. MC15-0
Brdcst / RX,SA 0. MC31-16
3FE
3C0
37F
383
341
302
Own Addr / Tx, SA 31. MC15-0
Own Addr / Tx, SA 0. MC15-0
Brdcst / Tx, SA 31. MC31-16
Own Addr / Rx, SA 1. WC31-16
Brdcst / Tx, SA 1.MC31-16
Brdcst / Rx, SA 1. WC15-0
3FF
3C1
380
342
303
Own Addr / Tx, SA 31. MC31-16
Own Addr / Tx, SA 0. MC31-16
Own Addr / Rx, SA 0. MC15-0
Brdcst / Tx, SA 1. WC15-0
Brdcst / Rx, SA 1. WC31-16
events/conditions include time tag rollover, RT address parity
error, RAM parity error, and BIT completed.
Bit 0 of the interrupt vector (interrupt status) word indicates
whether the entry is for a message interrupt event (if bit 0 is logic
"1") or a non-message interrupt event (if bit 0 is logic "0"). It is not
possible for one entry on the queue to indicate both a message
interrupt and a non-message interrupt.
As illustrated in FIGURE 10, for a message interrupt event, the
parameter word is a pointer. The pointer will reference the first
word of the RT or MT command stack descriptor (i.e., the Block
Status Word).
will be the RAM address where the parity check failed. For the
RT address Parity Error, Protocol Self-test Complete, and Time
Tag rollover non-message interrupts, the parameter is not used;
it will have a value of 0000.
If enabled, an INTERRUPT STATUS QUEUE ROLLOVER inter-
rupt will be issued when the value of the queue pointer address
rolls over at a 64-word address boundary.