Chapter 3 - MACSI Host Interface

Multiple Completed Returned IOPB Structure

When multiple commands are returned from the controller to the host with a single interrupt, the following structure is used to return individual commands, starting in the location of Short I/O normally used for the returned IOPB, and continuing for a maximum of 24 entries.

Table 3-10. Multiple Completed Returned IOPB Structure

Multiple Completed Returned IOPB Structure

Addr

15

14

13

12

11

10

9

8

 

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0x740

 

 

 

 

 

 

Command Tag

 

 

 

 

 

 

 

0x742

 

 

 

 

 

 

(4 Bytes)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0x744

 

 

 

 

 

 

Port

 

 

 

 

Work Queue Number

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0x746

 

 

 

 

 

 

Transfer Count

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Note: Port and Transfer Count fields are valid only if the posted element is a receive.

Command Tag

This field contains the command tag associated with the original command specified in the by the host in the Command Queue entry.

Port

For receives only, this field specifies the port on which in-coming frame was received. This field is not valid for

transmits.

Work Queue Number

This field contains the work queue number provided by the host in the original Command Queue entry.

Transfer Count

For receives only, this field specifies the size of the received frame subject to the same restriction as the returned frame size parameter in the normal receive IOPB: you must subtract 4 from this value to get the actual number of bytes transferred. This field is not valid for transmits.

64