Chapter 4 Command Operation

Page 4 - 6

 

The Base Status Block

The Base Status Block

Status Block

Format

The Status Block is another of the building blocks of the command structures you will be using when issuing commands. Used in conjunction with the Parameter Block, its purpose is to report the outcome of a command you issued.

The Status Block format is the same whether you have issued a Pass-through command or a Board-control command. It appears the same whether the command structure you used is a Single Command or a Command List, however there is a difference in the number of Status Blocks you may receive for each type of command structure.

Single Command structures return only one Status Block. The Single Command structure will contain only the last Status Block—the Status Block with the CC (Command Complete) bit of the Flags byte set.

When you are using a Command List structure, multiple Status Blocks for any one command are possible depending on the retry and Sense Byte selections you have made (with the Unit Options or Extended Unit Options Board-control commands).

The Status Block Format you will see used for all returned status information is illustrated in the following figure:

Address

 

Byte Memory Offset

 

Offset

Offset + 0

Offset + 1

Offset + 2

Offset +3

 

 

 

 

 

 

00H

 

Command Identifier

 

 

 

 

 

 

04H

 

 

Error

Flags

 

 

 

 

 

08H

 

Status Information

 

 

 

 

0CH

 

 

 

 

 

 

Table 18: Base Status Block

Following is a brief description of each of the fields:

Command Identifier - This value will identify which Parameter Block has completed.

Flags

This byte can be polled to determine whether, and in what condition, a command completed. It has this format:

BITS

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

CC

ERR

RTY

DTT

DTG

CSB

0

TMS

Table 19:

TMS Target Mode Status - This bit indicates that Status is being returned from the Target Mode Response command.

0 The status was not a result of a Target Mode Response command.

1 The status is the result of a Target Mode Response command.

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User’s Guide

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Ciprico Rimfire 3880 manual Status Block Format, Command Operation Base Status Block, Flags