CMX981 Consumer Microcircuits Limited, CMX981 Datasheet - Page 42

• Manufacturer Part Number: CMX981
• Description: Advanceddigital Radio Baseband Processor (tetra Etc.)
• Manufacturer: Consumer Microcircuits Limited

Advanced Digital Radio Baseband Processor
5.11.38 $4C-$4F
5.11.39 $50-$57
 2002 CML Microsystems Plc
These four address locations allow access to the 64 x 10-bit RAM. The contents of this RAM can
be pre-loaded with a table of values that can be automatically sent to the auxiliary DAC1 in either a
single cycle or continuous mode. Therefore the RAM can be used in conjunction with DAC1 to
enable user defined profile power ramping of an external RF power transmitter stage.
The RAM contents are addressed incrementally by first setting bit 2 of ConfigCtrl2 register. While
this bit is low, the RAM address pointer is held reset. The first two data words are written by writing
to addresses $4C to $4F in order. Accessing location $4F post-increments the address pointer.
Bit 3 of the ConfigCtrl2 register determines whether a read or write operation will increment the
RAM address pointer. Further write operations to addresses $4C to $4F, will load the next two
locations.
All locations are accessed incrementally; further accesses to this port while bit 3 of ConfigCtrl2 is
active are not valid and may cause data loss.
$50-$51
$52-$53
$54-$55
$56-$57
There are two input registers for each of the four auxiliary DACs. Writing to the LSB register ($50,
$52, $54 and $56) writes the two least significant bits of DAC data. Writing to the MSB register
($51, $53, $55 and $57) writes the eight most significant bits of DAC data and then passes all ten
bits to the appropriate DAC input. If the MSB register is written while the LSB register is left
constant, the converter may be treated as an 8-bit DAC.
$4C
$50, $52, $54, $56
$4D
$4E
$4F
$51, $53, $55, $57
Bit
Bit
Bit
Bit
Bit
Bit
Set this bit
Not used.
Not used.
Not used.
Set this
Set this
low.
bit low.
bit low.
7
7
7
7
7
7
AuxRamData
AuxDacData
AuxDacData1
AuxDacData2
AuxDacData3
AuxDacData4
Set this bit
Not used.
Not used.
Not used.
Set this
Set this
bit low.
bit low.
low.
6
6
6
6
6
6
Not used.
Not used.
Set this
Set this
bit low.
bit low.
Set this bit
Not used.
5
5
5
5
low.
5
5
Auxiliary DAC Memory I/O Access Addresses
Auxiliary DAC Data Registers (Write only)
Auxiliary DAC 1 Data Register
Auxiliary DAC 2 Data Register
Auxiliary DAC 3 Data Register
Auxiliary DAC 4 Data Register
42
Not used.
Not used.
Set this
Set this
bit low.
bit low.
Set this bit
DAC Data [9:2]
RAM data [9:2]
RAM data [9:2]
Not used.
4
4
4
4
low.
4
4
Not used.
Not used.
Set this
Set this
bit low.
bit low.
3
3
3
3
Set this bit
Not used.
low.
3
3
Not used.
Not used.
Set this
Set this
bit low.
bit low.
2
2
2
2
Set this bit
Not used.
low.
2
2
RAM data [1:0]
RAM data [1:0]
1
1
1
1
DAC Data [1:0]
1
1
0
0
0
0
CMX981
D/981/1
0
0