CMX838 View Datasheet(PDF) - CML Microsystems Plc
Part Name
Description
MFG CO.
'CMX838' PDF : 71 Pages View PDF
FRS/PMR446/GMRS Family Radio Processor
CMX838
4.2.4.5.3 Configure Aux Pin as Output (Task 14)
Task 14 can be used to select and enable various digital outputs at the AUX pin. Load the argument data in
register $95 then issue the task.
The argument data has the following format in the 8 bit task data register ($95).
Bit 7
Bit 6-3
1=enable aux
pin as output
0=enable aux
pin as input
Don’t care
Bit 2-0 (These bits are Don’t Care if Bit 7 is a logic 0)
Bit 2
1
1
1
1
Bit 1
0
0
1
1
Bit 0
0
1
0
1
AUX output signal
RX Decode Status bit
Audio Frequency Ringing Tone
Output logic 0
Output logic 1
For example to have the device produce a 620Hz ringing tone frequency set up the ringing frequency with
task 10 then enable the output with task 14. Note that once the Audio Ringing Generator is enabled the
frequency can be changed by reissuing task 10.
$8E 0x0986
$93 0x4A
// 620 Hz
wait 250µs
$95 0x85
$93 0x4E
wait at least 250 µs
$8E 0x06C2
$93 0x4A
// 440 Hz
4.2.4.5.4 Soft Reset (Task 15)
The tone signaling processor must be fully initialized after the chip is powered up. After powering up, the first
time the tone-signaling processor is enabled, it should be with the task field set to 15. This clears the
configuration memory and reverts to Fast Initialization Mode when any other task is issued. After all desired
initialization is performed, return to normal running mode by issuing task 0.
Power up Sequence
//Power up the Device
// issue general reset
$01
// set up base band clocks before enabling the sub-audio processor
$89 0xXX
// specific setting depends on your system (See Section 5.1.2.7)
$8A 0xXX
// specific setting depends on your system (See Section 5.1.2.8)
// issue Sub-audio processor soft reset
$93 0x4F
// wait for soft reset to complete
wait 250µs
// set up TX sub-audio frequency
$95 TX tone index
$93 0x48
// set up one RX sub-audio frequency
$95 (0x80 | RX tone index)
$93 0x44
// setup normal run mode for sub-audio processor
$93 (0x40 | IRQ control | Task 0)
// setup RX and TX sub-audio analog trimmers to 0dB
$97 0x1010
// setup other C-BUS registers as needed (e.g. Register $80 to select TX/RX , $88 for TX Mod 1 and Mod 2
Control, etc.)
2003 CML Microsystems Plc
25
D/838/8
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