GATT Vendor Specific API

GATT Commands

All GATT commands have the following format:

Name Size (bytes) Description
Opcode 2 PDU operation code
Connection Handle 2 Connection handle of the link
Command PDU Variable Command Parameters

For the command parameters, please see the corresponding section below.

Note: The connection handle of 0xFFFE is considered as the loopback connection. All messages sent to this connection will be loop backed to the local host.

Events Generated

For each GATT command,when it is received, the host will send the CommandStatus Event with the Status parameter. If a command will return additional events, it will be noted in the description below.

GATT_ExchangeMTU

Opcode:0xFD82
Command Description:
 This sub-procedure is used by a client to set the ATT_MTU to the maximum possible value that can be supported by both devices when the client supports a value greater than the default ATT_MTU for the Attribute Protocol. This sub-procedure shall only be initiated once during a connection.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
clientRxMTU:

Attribute client receive MTU size

Size:2 byte(s)
Default:23
Range:Any 2 byte value

Events Generated

This sub-procedure is complete when either ATT_ExchangeMTURsp (with SUCCESS or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_DiscAllPrimaryServices

Opcode:0xFD90
Command Description:
 This sub-procedure is used by a client to discover all the primary services on a server.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD

Events Generated

This sub-procedure is complete when either ATT_ReadByGrpTypeRsp (with bleProcedureComplete or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_DiscPrimaryServiceByUUID

Opcode:0xFD86
Command Description:
 This sub-procedure is used by a client to discover a specific primary service on a server when only the Service UUID is known. The specific primary service may exist multiple times on a server. The primary service being discovered is identified by the service UUID.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
value:

Attribute value to find

Size:input byte(s)
Default:“”
Range:Any (0 to (ATT_MTU - 7) byte) value

Events Generated

This sub-procedure is complete when either ATT_FindByTypeValueRsp (with bleProcedureComplete or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_FindIncludedServices

Opcode:0xFDB0
Command Description:
 This sub-procedure is used by a client to find include service declarations within a service definition on a server. The service specified is identified by the service handle range.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
startHandle:

First requested handle number

Size:2 byte(s)
Default:0x0001
Range:Any 2 byte value
endHandle:

Last requested handle number

Size:2 byte(s)
Default:0xFFFF
Range:Any 2 byte value

Events Generated

This sub-procedure is complete when either ATT_ReadByTypeRsp (with bleProcedureComplete or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_DiscAllChars

Opcode:0xFDB2
Command Description:
 This sub-procedure is used by a client to find all the characteristic declarations within a service definition on a server when only the service handle range is known. The service specified is identified by the service handle range.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
startHandle:

First requested handle number

Size:2 byte(s)
Default:0x0001
Range:Any 2 byte value
endHandle:

Last requested handle number

Size:2 byte(s)
Default:0xFFFF
Range:Any 2 byte value

Events Generated

This sub-procedure is complete when either ATT_ReadByTypeRsp (with bleProcedureComplete or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_DiscCharsByUUID

Opcode:0xFD88
Command Description:
 This sub-procedure is used by a client to discover service characteristics on a server when only the service handle ranges are known and the characteristic UUID is known. The specific service may exist multiple times on a server. The characteristic being discovered is identified by the characteristic UUID.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
startHandle:

First requested handle number

Size:2 byte(s)
Default:0x0001
Range:Any 2 byte value
endHandle:

Last requested handle number

Size:2 byte(s)
Default:0xFFFF
Range:Any 2 byte value
type:

2 or 16 octet UUID

Size:input byte(s)
Default:“00:00”
Range:Any 2 or 16 byte value

Events Generated

This sub-procedure is complete when either ATT_ReadByTypeRsp (with bleProcedureComplete or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_DiscAllCharDescs

Opcode:0xFD84
Command Description:
 This sub-procedure is used by a client to find all the characteristic descriptors Attribute Handles and Attribute Types within a characteristic definition when only the characteristic handle range is known. The characteristic specified is identified by the characteristic handle range.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
startHandle:

First requested handle number

Size:2 byte(s)
Default:0x0001
Range:Any 2 byte value
endHandle:

Last requested handle number

Size:2 byte(s)
Default:0xFFFF
Range:Any 2 byte value

Events Generated

This sub-procedure is complete when either ATT_FindInfoRsp (with bleProcedureComplete or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_ReadCharValue

Opcode:0xFD8A
Command Description:
 This sub-procedure is used to read a Characteristic Value from a server when the client knows the Characteristic Value Handle. The Read Response returns the Characteristic Value in the Attribute Value parameter.The Read Response only contains a Characteristic Value that is less than or equal to (ATT_MTU - 1) octets in length. If the Characteristic Value is greater than (ATT_MTU - 1) octets in length, GATT_ReadLongCharValue may be used if the rest of the Characteristic Value is required.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
handle:

The handle of the attribute to be read

Size:2 byte(s)
Default:0
Range:Any 2 byte value

Events Generated

This sub-procedure is complete when either ATT_FindInfoRsp (with bleProcedureComplete or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_ReadUsingCharUUID

Opcode:0xFDB4
Command Description:
 This sub-procedure is used to read a Characteristic Value from a server when the client knows the Characteristic Value Handle. The Read Response returns the Characteristic Value in the Attribute Value parameter. The Read Response only contains a Characteristic Value that is less than or equal to (ATT_MTU - 1) octets in length. If the Characteristic Value is greater than (ATT_MTU - 1) octets in length, GATT_ReadLongCharValue may be used if the rest of the Characteristic Value is required.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
startHandle:

First requested handle number

Size:2 byte(s)
Default:0x0001
Range:Any 2 byte value
endHandle:

Last requested handle number

Size:2 byte(s)
Default:0xFFFF
Range:Any 2 byte value
type:

2 or 16 octet UUID

Size:input byte(s)
Default:“00:00”
Range:Any 2 or 16 byte value

Events Generated

This sub-procedure is complete when either ATT_ReadByTypeRsp (with bleProcedureComplete or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_ReadLongCharValue

Opcode:0xFD8C
Command Description:
 This sub-procedure is used to read a Characteristic Value from a server when the client knows the Characteristic Value Handle and the length of the Characteristic Value is longer than can be sent in a single Read Response Attribute Protocol message.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
handle:

The handle of the attribute to be read

Size:2 byte(s)
Default:0
Range:Any 2 byte value
offset:

The offset of the first octet to be read

Size:2 byte(s)
Default:0
Range:Any 2 byte value

Events Generated

This sub-procedure is complete when either ATT_ReadBlobRsp (with bleProcedureComplete or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_ReadMultiCharValues

Opcode:0xFD8E
Command Description:
 This sub-procedure is used to read multiple Characteristic Values from a server when the client knows the Characteristic Value Handles. The Attribute Protocol Read Multiple Requests is used with the Set Of Handles parameter set to the Characteristic Value Handles. The ATT_ReadMultiRsp returns the Characteristic Values in the Set Of Values parameter.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
handles:

A set of two or more two-byte attribute handles

Size:input byte(s)
Default:“”
Range:Any (4 to (ATT_MTU-1) byte) value

Events Generated

This sub-procedure is complete when either ATT_ReadMultiRsp (with SUCCESS or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_WriteNoRsp

Opcode:0xFDB6
Command Description:
 This sub-procedure is used to write a Characteristic Value to a server when the client knows the Characteristic Value Handle and the client does not need an acknowledgment that the write was successfully performed. This sub-procedure only writes the first (ATT_MTU - 3) octets of a Characteristic Value. This sub-procedure can not be used to write a long characteristic; instead GATT_ReadLongCharValue should be used.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
handle:

The handle of the attribute to be set

Size:2 byte(s)
Default:0
Range:Any 2 byte value
value:

The value to be written to the attribute

Size:input byte(s)
Default:“”
Range:Any (0 to (ATT_MTU - 3) byte) value

Events Generated

No response will be sent to the calling application task for this sub-procedure. If the Characteristic Value write request is the wrong size, or has an invalid value as defined by the profile, then the write will not succeed and no error will be generated by the server.

GATT_SignedWriteNoRsp

Opcode:0xFDB8
Command Description:
 This sub-procedure is used to write a Characteristic Value to a server when the client knows the Characteristic Value Handle and the ATT Bearer is not encrypted. This sub-procedure shall only be used if the Characteristic Properties authenticated bit is enabled and the client and server device share a bond as defined in the GAP. This sub-procedure only writes the first (ATT_MTU - 15) octets of an Attribute Value. This sub-procedure cannot be used to write a long Attribute.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
handle:

The handle of the attribute to be set

Size:2 byte(s)
Default:0
Range:Any 2 byte value
value:

The value to be written to the attribute

Size:input byte(s)
Default:“”
Range:Any (0 to (ATT_MTU - 3) byte) value.

Events Generated

No response will be sent to the calling application task for this sub-procedure. If the authenticated Characteristic Value that is written is the wrong size, or has an invalid value as defined by the profile, or the signed value does not authenticate the client, then the write will not succeed and no error will be generated by the server.

GATT_WriteCharValue

Opcode:0xFD92
Command Description:
 This sub-procedure is used write a characteristic value to a server when the client knows the characteristic value handle. This sub-procedure only writes the first (ATT_MTU-3) octets of a characteristic value. This sub-procedure can not be used to write a long attribute; instead the Write Long Characteristic Values sub-procedure should be used.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
handle:

The handle of the attribute to be set

Size:2 byte(s)
Default:0
Range:Any 2 byte value
value:

The value to be written to the attribute

Size:input byte(s)
Default:“”
Range:Any (0 to (ATT_MTU - 3) byte) value

Events Generated

This sub-procedure is complete when either ATT_WriteRsp (with SUCCESS or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_WriteLongCharValue

Opcode:0xFD96
Command Description:
 This sub-procedure is used to write a Characteristic Value to a server when the client knows the Characteristic Value Handle but the length of the Characteristic Value is longer than can be sent in a single Write Request Attribute Protocol message.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
handle:

The handle of the attribute to be written

Size:2 byte(s)
Default:0
Range:Any 2 byte value
offset:

The offset of the first octet to be written

Size:2 byte(s)
Default:0
Range:Any 2 byte value
value:

The value of the attribute to be written. Note: the stack implementation supports the maximum length of 512 octets but this is always bound by the physical interface used to communicate with the device

Size:input byte(s)
Default:“”
Range:Any 0 to 512 byte value.

Events Generated

This sub-procedure is complete when either ATT_PrepareWriteRsp (with bleTimeout status), ATT_ExecuteWriteRsp (with SUCCESS or bleTimeout status), or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_ReadCharDesc

Opcode:0xFDBC
Command Description:
 This sub-procedure is used to read a Characteristic Descriptor from a server when the client knows the Characteristic Descriptors Handle.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
handle:

The handle of the attribute to be read

Size:2 byte(s)
Default:0
Range:Any 2 byte value

Events Generated

This sub-procedure is complete when either ATT_ReadRsp (with bleProcedureComplete or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_ReadLongCharDesc

Opcode:0xFDBE
Command Description:
 This sub-procedure is used to read a Characteristic Descriptor from a server when the client knows the Characteristic Descriptor Declarations Attribute Handle and the length of the Characteristic Descriptor Declaration is longer than can be sent in a single Read Response Attribute Protocol message.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
handle:

The handle of the attribute to be read

Size:2 byte(s)
Default:0
Range:Any 2 byte value
offset:

The offset of the first octet to be read

Size:2 byte(s)
Default:0
Range:Any 2 byte value

Events Generated

This sub-procedure is complete when either ATT_ReadBlobRsp (with bleProcedureComplete or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_WriteCharDesc

Opcode:0xFDC0
Command Description:
 This sub-procedure is used write a characteristic descriptor to a server when the client knows the characteristic descriptor handle.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
handle:

The handle of the attribute to be set

Size:2 byte(s)
Default:0
Range:Any 2 byte value
value:

The value to be written to the attribute

Size:input byte(s)
Default:“”
Range:Any (0 to (ATT_MTU - 3) byte) value

Events Generated

This sub-procedure is complete when either ATT_WriteRsp (with SUCCESS or bleTimeout status) or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_WriteLongCharDesc

Opcode:0xFDC2
Command Description:
 This sub-procedure is used to write a Characteristic Value to a server when the client knows the Characteristic Value Handle but the length of the Characteristic Value is longer than can be sent in a single Write Request Attribute Protocol message.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
handle:

The handle of the attribute to be written

Size:2 byte(s)
Default:0
Range:Any 2 byte value
offset:

The offset of the first octet to be written

Size:2 byte(s)
Default:0
Range:Any 2 byte value
value:

The value of the attribute to be written. Note: the stack implementation supports the maximum length of 512 octets but this is always bound by the physical interface used to communicate with the device

Size:input byte(s)
Default:“”
Range:Any 0 to 512 byte value.

Events Generated

This sub-procedure is complete when either ATT_PrepareWriteRsp (with bleTimeout status), ATT_ExecuteWriteRsp (with SUCCESS or bleTimeout status), or ATT_ErrorRsp (with SUCCESS status) is received by the calling application task.

GATT_Notification

Opcode:0xFD9B
Command Description:
 This sub-procedure is used when a server is configured to notify a characteristic value to a client without expecting any attribute protocol layer acknowledgment that the notification was successfully received. Note: A notification may be sent at any time and does not invoke a confirmation.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
authenticated:

Whether or not an authenticated link is required

Size:

1 byte(s)

Default:

0x00

Range:
Value Description
0x00 No
0x01 Yes
handle:

The handle of the attribute

Size:2 byte(s)
Default:0
Range:Any 2 byte value
value:

The current value of the attribute

Size:input byte(s)
Default:“”
Range:Any (0 to (ATT_MTU - 3) byte) byte value.

Events Generated

This command only returns the CommandStatus event

GATT_Indication

Opcode:0xFD9D
Command Description:
 This sub-procedure is used when a server is configured to indicate a characteristic value to a client and expects an attribute protocol layer acknowledgment that the indication was successfully received.

Command Parameters

Connection Handle:
 

Identifies the connection.

Size:2 byte(s)
Default:0x0000
Range:0x0000 to 0xFFFD
authenticated:

Whether or not an authenticated link is required

Size:

1 byte(s)

Default:

0x00

Range:
Value Description
0x00 No
0x01 Yes
handle:

The handle of the attribute

Size:2 byte(s)
Default:0
Range:Any 2 byte value
value:

The current value of the attribute

Size:input byte(s)
Default:“”
Range:Any (0 to (ATT_MTU - 3) byte) value

Events Generated

This sub-procedure is complete when ATT_HandleValueCfm (with SUCCESS or bleTimeout status) is received by the calling application task.

GATT_AddService

Opcode:0xFDFC
Command Description:
 This command is used to add a new service to the GATT Server on the Network Processor when the GATT Database is implemented on the Application Processor. The GATT_AddAttribute must be used to add additional attributes to the service. The new service will be automatically registered with the GATT Server if it has no additional attribute to be added. Note: The Command Status Event will have the Start Handle and End Handle for the service registered with the GATT Server. No ATT request is used to perform this command.

Command Parameters

UUID:

The type of the service to be added (primary or secondary)

Size:

2 byte(s)

Default:

0x2800

Range:
Value Description
0x2800 PrimaryService
0x2801 SecondaryService
numAttrs:

The number of the attributes in the service (including the service attribute)

Size:2 byte(s)
Default:1
Range:Any 2 byte value
encKeySize:

The minimum encryption key size (in octets) required by the service.

Size:1 byte(s)
Default:16
Range:7-16

Events Generated

This command only returns the CommandStatus event

GATT_DelService

Opcode:0xFDFD
Command Description:
 This command is used to delete a service from the GATT Server on the Network Processor when the GATT Database is implemented on the Application Processor.

Command Parameters

handle:

The handle of the service to be deleted

Size:2 byte(s)
Default:0
Range:Any 2 byte value

Events Generated

This command only returns the CommandStatus event

GATT_AddAttribute

Opcode:0xFDFE
Command Description:
 This command is used to add a new attribute to the service being added to the GATT Server on the Network Processor when the GATT Database is implemented on the Application Processor. The service will be automatically registered with the GATT Server when its last attribute is added. Note: The Command Status Event will have the Start Handle and End Handle for the service registered with the GATT Server.

Command Parameters

UUID:

The type of the attribute to be added

Size:input byte(s)
Default:“”
Range:Any 2 byte value
permissions:

Attribute access permissions

Size:

1 byte(s)

Default:

0x01

Range:
Value Description
0x01 GATT_PERMIT_READ
0x02 GATT_PERMIT_WRITE
0x04 GATT_PERMIT_AUTHEN_READ
0x08 GATT_PERMIT_AUTHEN_WRITE
0x10 GATT_PERMIT_AUTHOR_READ
0x20 GATT_PERMIT_AUTHOR_WRITE
0x40 GATT_PERMIT_ENCRYPT_READ
0x80 GATT_PERMIT_ENCRYPT_WRITE
0x40 GATT_PERMIT_ENCRYPT_READ

Events Generated

This command only returns the CommandStatus event

GATT Events

All GATT events have the following format:

Name Size (bytes) Description
Opcode 2 PDU operation code
Status 1 Event status
Connection Handle 2 Connection handle of the link
PDU length 1 Length of event PDU
Event PDU Variable Event parameters

For the event parameters, please see the corresponding section below.

Note: The connection handle of 0xFFFE is considered as the loopback connection. All messages sent to this connection will be loop backed to the local host.

GATT_ClientCharCfgUpdated

Opcode:0x0580
Event Description:
 A GATT Client Characteristic Configuration has been updated.

Event Parameters

Status:
Size:

1 byte(s)

Range:
Value Description
0x00 SUCCESS
0x12 bleIncorrectMode
0x02 INVALIDPARAMETER
connectionHandle:
 

Connection handle of the link

Size:2 byte(s)
Range:Any 2 byte value
pduLen:

PDU length

Size:1 byte(s)
Range:Any 1 byte value
attributeHandle:
 

Handle of the CCC

Size:2 byte(s)
Range:
value:

New Value of the CCC.

Size:2 byte(s)
Range: