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
6.6.2.1 Register Descriptions:
GENERAL RESET ($01): (if required)
SYNTHESIZER BASEBAND CLOCK CONTROL ($89): 10010000b = $90
• baseband and synthesizer reference clock from REF IN, xtal amp disabled (10)
• REF IN frequency 12.8MHz (0100)
• Bits 1-0 are don’t cares as xtal is not used
SETUP ($80): 11111110b = $FE
• Tx Enabled (1)
• Audio input supplied by microphone output (11)
• Audio signal passed through HPF to limiter (1111)
• Bit 0 is unused (0)
AUDIO CONTROL ($81): 00010000b = $10
• Audio signal passed through pre-emphasis filter and HPF (000)
• Audio level set to 0.0dB (10000)
RX AUDIO LEVEL CONTROL ($82): 00010111b = $17
• Deviation limiter not bypassed (0)
• Post deviation limiter LPF not bypassed (0)
• De-emphasis network not bypassed (0)
• Rx volume control set to 0.0dB (10111)
AUDIO POWER AND BANDWIDTH CONTROL ($83): 01010100b = $54
• Modulation digitally controlled amplifiers (DCA) and microphone amplifier configured for normal
operation (01)
• Audio filters, deviation limiter, and audio level DCA configured for normal operation (01)
• De-emphasis network and Rx Audio Out DCA configured for normal operation (01)
• Post deviation limiter LPF set to wide setting (0)
• Bit 0 is unused (0)
TX MOD 1 & 2 CONTROL ($88): 00000000 01110000b = $0070
• Tx Mod 2 output set to Vbias (000)
• Tx Mod 2 output gain set to off (00000)
• Tx Mod 1 output set to Audio + Tone (011)
• Tx Mod 1 output gain set to 0.0dB (10000)
SYNTHESIZER GENERAL CONTROL ($8A): 01010100b = $54
• Synthesizer is enabled (01)
• Lock detect IRQ is enabled, status updated every phase comparison when the last two comparisons
disagree (01)
• Magnitude of charge pump current is 40*Iset (0)
• Positive VCO gain slope (1)
• FRS channels selected (00)
SYNTHESIZER CHANNEL SELECT ($8B): 00000001b = $01
• Bits 7 and 6 set to zero (00)
• Lock detect comparison window set to +/- 20ns (00)
• FRS channel 1 selected (0001)
TONE SIGNALING CONTROL REGISTER ($93): 01001111b = $4F
• Enable power (01)
• No IRQ (00)
• Subaudio processor ‘soft reset’ (1111)
8 BIT SUBAUDIO TASK DATA ($95): 00010000b = $10
• Load 110.9Hz tone (00010000)
2003 CML Microsystems Plc
59
D/838/8
Share Link: 
