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EDS Schema

F. Torelli & P. SkrzypekCCSDS Spring Meeting 201316/04/2013

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Contents

• General Layout

• Interface description

• Data types

• Process description

• Process instructions

• Summary

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GENERAL LAYOUT

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General layout

Contents of the SOIS EDS• Functional interface (FI)

• Device-specific interface (DSI)

• Subnetwork interface:

• Packet interface (PI)

• Memory interface (MI)

• Device-specific access protocol (DSAP)

• Device abstraction control procedure (DACP)

• Unambiguous documentation

Addressed in this presentation

Not addressed in this presentation. This issue will be addressed later, by analyzing other formats: SensorML, XidML, etc.

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DAS inputs

DVS inputs

Application inputs

Device data types

MIPI

General layout

FI

DACP

DSI

DSAP

PI MI

Interface description• lists all available relations• defines all data types used• independent of other EDS parts

Process description• dependent on surrounding interfaces• may define internal data types

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INTERFACE DESCRIPTION

Functional interfaceDevice-specific interfacePacket interfaceMemory interface

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Functional / Device-specific interface

this section lists all possible relations

relation which can be aquired

relation which can be commanded

relation is identified by value_id type

value_id is a type with constraints

value_id may contain other fields

structure of exchanged data

structure of associated metadata

this section defines all data types used

1. <functional_interface class="thermistor">    2.   3.   <interface>    4.   5.     <acquire>    6.       <value_id type="temperature_reading_t"/>    7.       <value type="temperature_t"/>    8.       <metadata type="bivalent_t"/>    9.     </acquire>     10.   11.     <command>    12.       <value_id type="alter_refresh_rate_t"/>    13.       <value type="interval_t"/>    14.       <metadata type="bivalent_t"/>    15.     </command>    16.   17.   </interface>    18.   19.   <data_types>    20.   21.     <sequence name="temperature_reading_t">    22.       <declare name="header" type="value_id_header_t">  

  23.         <constraint field="service">    24.           <option name="read_temperature"/>    25.         </constraint>    26.       </declare>    27.       <declare name="unit" type="thermistor_unit_t"/

>    28.     </sequence>    29.   30.     <!-- temperature_t, bivalent_t, thermistor_unit_t  -

->  31.     <!-- alter_refresh_rate_t, interval_t, ... -->  32.   33.   </data_types>    34.   35. </functional_interface>  

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Packet interface

1. <packet_interface>    2.   3.   <interface>    4.   5.     <packet>    6.       <data type="speed_pkt"/>    7.     </packet>    8.   9.     <packet>    10.       <data type="status_pkt"/>    11.     </packet>    12.   13.   </interface>    14.   15.   <data_types>    16.   17.     <sequence name="speed_pkt">  18.       <declare name="header" type="pkt_header">  19.         <constraint field="id">  20.           <option name="speed"/>  21.         </constraint>  22.       </declare>  23.       <declare name="speed" type="speed_t"/>  24.     </sequence>  25.   26.   </data_types>    27.   28. </packet_interface>

this section lists all possible packets

a packet is identified by its distinctive structure

this section defines all data types used

constraints are used to identify a particular packet type

other fields present inside a packet

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Memory interface

1. <memory_interface>  2.   3.   <interface>  4.   5.     <memory>  6.       <memory_id type="sram_id_t"/>  7.       <map>    8.         <region name="uart1" offset="0x90000000" type="uart_peripheral_t"/

>    9.       </map>    10.       <metadata type="bivalent_t"/>    11.     </memory>    12.   13.     <memory>    14.       <memory_id type="flash_id_t"/>    15.       <map>    16.         <region name="vectors" offset="0x00000000" type="interrupt_vectors_t"

/>    17.       </map>    18.       <metadata type="bivalent_t"/>    19.     </memory>    20.   21.   </interface>    22.   23.   <data_types>    24.     <!-- .. -->  25.   </data_types>    26.   27. </memory_interface>  

this section lists all possible memory locations

this type corresponds to memory_id field in MAS

this field corresponds to the start_address field in MAS

memory data is mapped on a structure to avoid bit operations

memory is accessed using the name of the region

structure of associated meta data

This section defines all data types used

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DATA TYPES

intfloatarraysequence

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Data types

Integer number

- value constraints

- binary encoding rules

Enumeration field

- value constraints

- binary encoding rules

Floating point number

- value constraints

- binary encoding rules

Blob data

- value constraints

- binary encoding rules

- dynamic length

Array

- dynamic length

Sequence

- can be sub-constrained

- may contain one component of dynamic length

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PROCESS DESCRIPTION

Device abstraction control procedureDevice-specific access protocol

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Process description

1. <device_abstraction_control_procedure>  2.   3.   <request_handler>    4.   5.     <variables>    6.       <declare name="id" type="temperature_reading_t"/>    7.       <declare name="data" type="temperature_t"/>    8.       <declare name="meta" type="bivalent_t"/>    9.     </variables>    10.   11.     <value_id>    12.       <variable name="id"/>    13.     </value_id>    14.   15.     <value>    16.       <variable name="data"/>    17.     </value>    18.   19.     <metadata>    20.       <variable name="meta"/>    21.     </metadata>    22.   23.     <process>    24.       <!-- instructions -->  25.     </process>    26.   27.   </request_handler>    28.   29. </device_abstraction_control_procedure> 

Declares variables used inside process description

connects id variable to value_id contents

connects data variable to the value of relation

connects meta variable to meta data information

description of the process

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Process description

das_meta = success

dvs_meta := failure

linear_calibrationslope <= 1bias <= -100input <= temperature_rawoutput <= temperature_kelvin

dvs_meta := success

Y N

1. <compare>  2.   <subject>  3.     <variable name="das_meta"/>  4.   </subject>  5.   <reference>  6.     <const value="success"/>  7.   </reference>  8.   <equal>  9.     <linear_calibration>  10.       <slope> <const value="1"/> </slope>  11.       <bias> <const value="-100"/> </bias>  12.       <input> <variable name="temperature_raw"/> </input>  13.       <output> <variable name="temperature_kelvin"/> </output>  14.     </linear_calibration>  15.     <copy>  16.       <destination>  17.         <variable name="dvs_meta"/>  18.       </destination>  19.       <source>  20.         <const value="success"/>  21.       </source>  22.     </copy>  23.   </equal>  24.   <not_equal>  25.     <copy>  26.       <destination>  27.         <variable name="dvs_meta"/>  28.       </destination>  29.       <source>  30.         <const value="failure"/>  31.       </source>  32.     </copy>  33.   </not_equal>  34. </compare> 

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PROCESS INSTRUCTIONS

compareloopsois serviceslinear calibration

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Process instructions

Data handling

- variables

- aliases

- immediate values

- arithmetic operations

Calibration

- linear calibration

SOIS services

- using DAS

- using PS

- using MAS

Flow control

- loops

- conditinal statements

this list will be extended

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SUMMARY

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Summary

• Outline of the general layout

• Quick introduction how to describe interfaces using data types

• Quick introduction how to describe processes using predefined

instructions

• For more details, especially on constraining data types, refer to the

attached document