CMX838D1 View Datasheet(PDF) - CML Microsystems Plc
Part Name
Description
MFG CO.
'CMX838D1' PDF : 71 Pages View PDF
FRS/PMR446/GMRS Family Radio Processor
CMX838
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): 00111110b = $3E
• Rx Enabled (0)
• Audio input signal supplied from RX Input (01)
• Audio signal passed through HPF out to limiter (1111)
• Bit 0 is unused (0)
AUDIO CONTROL ($81): 01010000b = $50
• First stage filtering configured as LPF (01)
• Audio signal passed through HPF (0)
• Audio level set to 0.0dB (10000)
RX AUDIO LEVEL CONTROL ($82): 11010111b = $D7
• Deviation limiter bypassed (1)
• Post deviation limiter LPF bypassed (1)
• Audio signal passed through de-emphasis network (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 00000000b = $0000
• Tx Mod 2 output set to Vbias (000)
• Tx Mod 2 output gain set to off (00000)
• Tx Mod 1 output set to Vbias (000)
• Tx Mod 1 output gain set to off (00000)
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 ($93): 01001111b = $4F
• Enable power (01)
• No IRQ (00)
• Subaudio processor ‘soft reset’ (1111)
- this task is only required when the subaudio processor is enabled the first time after power up
(‘General Reset’ alone does not require the ‘soft reset’ task to be issued)
2003 CML Microsystems Plc
61
D/838/8
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