Command response block (crb), Command response status word (crsw) – Interphase Tech CONDOR 4221 User Manual
Page 74
Chapter 3 - MACSI Host Interface
62
Command Response Block (CRB)
The CRB is used by the controller to post completed commands back to the host. It consists of the following fields:
Table 3-8. Command Response Block
Command Response Status Word (CRSW)
The CRSW describes the nature of the response, and includes a handshake bit similar to the CQE Go bit to synchronize
the controller and the host.
Table 3-9. Command Response Block
Command Response Block Valid (CRBV)
The controller sets this bit after assembling the returned commands in host accessible memory. If Offboard
postbacks are enabled, the returned commands will be located in both the onboard memory and the offboard
memory. If commands are being returned one at a time (single completion), the entire IOPB will be located
in the Returned IOPB space. If multiple commands are being returned, several Multiple Command return
structures will located in Short I/O, starting at the same location as used for the returned IOPB.
Command Complete (CC)
This bit is set when an IOPB is being returned. If this bit is set, a returned IOPB will be located in Short I/O.
Command Response Block
Addr
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0x730
Command Response Status Word (CRSW)
0x732
Reserved
0x734
0x736
Command Tag
(4 Bytes)
0x738
Reserved
Work queue number
0x73A
to
0x73E
Reserved
(8 Bytes)
Command Response Block
Addr
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0x730
MC
QMS CE
EX
ER
CC
CRBV