User's Manual

Enhanced Class 1 Bluetooth v2.1 Module
User’s Guide
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CONN-GUIDE-BT740_v0.2
11.2 Malloc Statistics
This event conveys pool malloc statistics to the host and is available in engineering/beta builds only.
Event Packet
Offset
Field
Value
Comments
0
LENGTH
16
1
CHANNEL
0
2
EVENT
[EVT_DEBUG_PACKET]
3
FLOW_OUT
??
Runtime value
4..5
ELSIZE[2]
0..N
Pool Element Size
6..7
NUMELS[2]
0..N
Number of elements
8..9
TAKEN[2]
0..N
Number of elements taken
10..11
MAXTKN[2]
0..N
Tide mark for taken
12..13
OVFLO[2]
0..N
Number of allocations from
next bigger element because
this size is maxed out
12 DATA CHANNELS
This section provides details of some data channels which require further explanation.
12.1 HDP Data Channels
12.1.1 Host to Module Direction
Channels B0 and B1 upload attribute data which then transfers to the appropriate data specialization data
variable on receipt of a CMD_HDP_ATTRUBUTE_WRITE command.
The host ensures that the correct number of bytes for that attribute accumulate in the channel, as length
is the only validation performed on the data; the module does not interpret the data in any way besides
length. With regards to the endienness of the data, this shall be determined by trial and error using an
appropriate certified HDP manager.
It is entirely possible that an attribute can be defined which contains data requiring more than 253 bytes.
A data packet cannot contain data more than 253 bytes so this could present a problem. The solution to
that is both channels B0 and B1 write into a buffer in the module to allow the host to accumulate attribute
data using several data packets. However when using B0 it always first deletes any data already
accumulated in the buffer and then writes to that buffer, whereas writing to channel B1 shall always
append the data to the buffer.
12.1.2 Module to Host Direction
Channels B0 and B1 send logical HDP packets to the host. Channel B0 is always the first fragment of the
logical packet and subsequent fragments send in channel B1. This means that when the host receives a
packet on channel B0, it deletes all data accumulated for an existing ongoing logical packet.