UM1755 Datasheet, PDF (14/123 Pages) STMicroelectronics – The purpose of this document is to describe the design of the application

Vendor specific commands
4
Vendor specific commands
UM1755
The VS commands can be either ACI VS commands to access the host of the BlueNRG, or
the HCI VS commands to access the LE controller. Both types of the commands use the
OGF value of 0x3F.
4.1
VS command and VS event format
The OCF field of the OpCode of the VS commands is further divided into two fields:
Command Group ID and Command ID.
Figure 7. OpCode format for VS Commands
 %LWV
2*) 
 
&RPPDQG*URXS,' 
&*,'
ELWV 
2&)
&RPPDQG,'&,' 
ELWV 
*$066*
Figure 7 above gives the 16-bit OpCode format (see also Section 2.2). The OGF field is
always 0x3F for VS commands. The 10-bit OCF field is split into two parts: 3-bit Command
Group ID (CGID) and 7-bit Command ID (CID). The CGID is used by the BlueNRG ACI
interface to route the commands to different logical layers, e.g. L2CAP, GAP, GATT, etc. It
also helps to categorize the VS commands with a more clear structure. The CID determines
the ID of each command. Each CGID group can have up to 128 VS commands.
Command group
HCI
GAP
GATT
L2CAP
Reserved
Table 4. CGID group
Description
HCI extension commands
Generic access profile commands
Generic attribute profile commands
L2CAP commands
CGID
0x0
0x1
0x2
0x3
0x4 – 0x7
The VS event also has a slightly different format than the standard HCI event (see also
Section 2.3). (1) The 8-bit event code of the VS event always has the value of 0xFF. (2) The
16-bit event parameter 0 has a different format.
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