
33
Data Device Corporation
www.ddc-web.com
BU-65743/65843/65863/65864
D-06/04-0
Subaddress -
specific circular buffer
of specified size.
8192-Word
1
(for
receive
and
/
or
broadcast
subaddresses
only)
Global Circular Buffer: The buffer size is specified by Configuration
Register #6, bits 11-9. The pointer to the global circular buffer is
stored at address 0101h (for Area A, PCI BAR0 offset 0202h) or
address 0105h (for Area B, PCI BAR0 offset 020Ah)
1
0
1
4096-Word
0
1
0
1
1024-Word
0
1
512-Word
1
0
256-Word
0
1
0
128-Word
1
0
Reserved for future use
Single Message
0
1
0
SUBADDRESS CONTROL WORD BITS
MM0
MEMORY MANAGEMENT SUBADDRESS
BUFFER SCHEME DESCRIPTION
MM1
GLOBAL CIRCULAR
BUFFER (bit 15)
MM2
TABLE 56. RT SUBADDRESS CONTROL WORD - MEMORY MANAGEMENT OPTIONS
2048-Word
1
0
1
For the case of a receive (or broadcast receive) message with a
data word error, there is an option such that the lookup table
pointer will only be updated following receipt of a valid message.
That is, the pointer will not be updated following receipt of a
message with an error in a data word. This allows failed mes-
sages in a bulk data transfer to be retried without disrupting the
circular buffer data structure, and without intervention by the
RT's host processor.
GLOBAL CIRCULAR BUFFER
Beyond the programmable choice of single buffer mode, double
buffer mode, or circular buffer mode, programmable on an indi-
vidual subaddress basis, the PCI Mini-ACE Mark3/Micro-ACE TE
architecture provides an additional option, a variable sized glob-
al circular buffer. The PCI Mini-ACE Mark3/Micro-ACE TE RT
allows for a mix of single buffered, double buffered, and individ-
ually circular buffered subaddresses, along with the use of the
global double buffer for any arbitrary group of receive(/broadcast)
or broadcast subaddresses.
Subaddress
Control Word
Lookup Table
(OPTIONAL)
SACW SA0
SACW SA31
0440
047E
0220
023F
Broadcast
Lookup
Pointer
Table
(Optional)
Bcst SA0
Bcst SA31
0400
043F
0200
021F
Transmit
Lookup
Pointer
Table
Tx SA0
Tx SA31
03C0
03FE
01E0
01FF
Receive
(/Broadcast)
Lookup
Pointer
Table
Rx(/Bcst) SA0
Rx(/Bcst) SA31
0380
03BE
01C0
01DF
COMMENT
DESCRIPTION
TABLE 55. RT LOOK-UP TABLES (ALL ADDRESSES IN HEX)
0340
037E
01A0
01BF
0300
033E
0180
019F
02C0
02FE
0160
017F
0280
02BE
0140
015F
AREA A
(INTERNAL MEMO-
RY OFFSET
AREA A
(PCI BAR0
OFFSET)
AREA B
(INTERNAL MEM-
ORY OFFSET)
AREA B
(PCI BAR0
OFFSET)