CMX980AL7 CML Microcircuits, CMX980AL7 Datasheet - Page 37

• Manufacturer Part Number: CMX980AL7
• Description: TETRA Baseband Processor
• Manufacturer: CML Microcircuits

TETRA Baseband Processor
Title:
Address:
Function:
Description:
Bit
7
6
5
4
3
2
1
1999 Consumer Microcircuits Limited
AdcConvertRate
AdcContConv
EnableAdc4
EnableAdc3
EnableAdc2
EnableAdc1
AuxAdcCtrl
Name
Auxiliary ADC data converter Control register
$0x0B
RW
This register controls the operation of the four ADC channels. These are implemented using a
single ADC converter which is multiplexed on to each of the ADC channels. A conversion cycle
consists of performing a conversion for each of the active channels in turn, in the order channel
1, channel 2, channel 3, channel 4. Note that when no channel is active, or when in one-shot
mode and conversions on all active channels have completed, the analogue ADC circuitry is
automatically powered down.
High
High
High
High
High
High
Active State
RW
RW
RW
RW
RW
RW
RW
Reserved. This bit should be set Low. Undefined on read.
This bit changes the ADC conversion rate. If this bit is set
Low, the ADC is clocked by MCLK/8, yielding a conversion
time of 80x MCLK periods per ADC channel. The maximum
sample rate is lower than this. With a single channel
selected, the maximum rate is MCLK/84 samples/second.
Setting this bit high will halve the ADC clock rate, and hence
double the conversion time.
Continuous conversion mode control bit; when inactive, sets
the ADCs into one-shot conversion mode; when active, the
ADCs will continuously convert. One-shot conversion mode
is initiated by the StartConvert bit. In continuous convert
mode, the ADC will start a new conversion cycle on all active
channels after the previous cycle has completed.
Setting this bit high will enable ADC channel 4 for
conversion. This bit may be updated at any time, but will
only change the active state of the ADC channel for the next
time it is converted.
Setting this bit high will enable ADC channel 3 for
conversion. This bit may be updated at any time, but will
only change the active state of the ADC channel for the next
time it is converted.
Setting this bit high will enable ADC channel 2 for
conversion. This bit may be updated at any time, but will
only change the active state of the ADC channel for the next
time it is converted.
Setting this bit high will enable ADC channel 1 for
conversion. This bit may be updated at any time, but will
only change the active state of the ADC channel for the next
time it is converted.
37
Function
CMX980A
D/980A/3