User's Manual

Class 1 Bluetooth v2.0 Module
User’s Guide
Americas: [phone] Option 2
Europe: [phone]
Hong Kong: [phone]
www.lairdtech.com/bluetooth
32
CONN-GUIDE-BT730_v0.9
Reg.
#
Defaul
t
Range
Comment
S551
0x321
1
0xFFFF
This register specifies in each 4 bit nibble, how the outgoing modem
status bits to the remote peer gets its value. Bluetooth allows for
RTR, RTC, DV, and IC bits to be exchanged over an RFCOMM
connection.
Nibble 0..3 specifies the source for RTC
4..7 specifies the source for RTR
8..11 specifies the source for DV (i.e. DCD)
12..15 specifies the source for IC (i.e. RI)
Each nibble can take the following value:
 0 – Always set to 0
 1 – Always set to 1
 2 – If DCD (pin 8 on module connector) is output then always 1
If DCD is input then 1 if DCD is asserted otherwise 0
 3 – If RI (pin 6) is output then always 0
If RI is input then 1 if RI is asserted otherwise 0
If DSR (pin 10) is asserted then 1 otherwise 0
In the event that a nibble specifies DSR as the source of its state, be
aware that if S Register 507 is anything other than 0, a de-assertion
of DSR causes the Bluetooth connection to be dropped.
If bits 0..3 and 4..7 are set to 0, then some Bluetooth devices will use
that as a signal to stop sending any data back. For example, Nokia
6310 stops responding.
If this register is changed while in command and connected mode,
then on going back online using the ATO command, a fresh signal is
sent to the peer to update the bits.
S552
0x012
2
0x0FFF
This register specifies in each 4 bit nibble, how the DTR, DCD, RI
output pins are controlled when in a Bluetooth connection
Nibble 0..3 specifies the source for DTR
4..7 specifies the source for DCD
8..11 specifies the source for RI
Each nibble can take the following value:
 0 – Do NOT touch the I/O
 1 – Always deassert
 2 – Always assert
 3 – If RTC bit in CONTROL_IND is 1 then assert otherwise
deassert
 4 – If RTR bit in CONTROL_IND is 1 then assert otherwise
deassert
 5 – If DV bit in CONTROL_IND is 1 then assert otherwise
deassert
 6 – If IC bit in CONTROL_IND is 1 then assert otherwise deassert
If this register is changed while in command and connected mode,
then on going back online using the ATO command, the modem
output lines are refreshed.