CMX981 Consumer Microcircuits Limited, CMX981 Datasheet - Page 40

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

Advanced Digital Radio Baseband Processor
5.11.34 $36-$37
5.11.35 $38-$3B
 2002 CML Microsystems Plc
The value written in this register controls the signal offset. The equation for this is:
The value of this register is in 2's complement format. Inappropriate values may cause arithmetic
overflow.
$38-$39
$3A-$3B
These registers allow direct access to the receive data path values just after the gain and offset
adjustment. Both read and write operations are permitted. A read operation reads the signal
values on the I and Q channels. A write operation will write data to the data path operator output.
To prevent normal data overwriting these values, bit 2 in the LoopBackCtrl register should be set.
The MSB read data is buffered to enable access of a discrete sample value (if the register was not
buffered, data from different sample periods could be in the MSB and LSB registers). Therefore,
the LSB register must be read first for correct operation.
$36
$38, $3A
$37
$39, $3B
Bit
Bit
Bit
Bit
7
7
7
7
RxQOffset
D
RxDPData
RxDPIData
RxDPQData
out
= D
in
6
6
+ [N
6
6
off
/ 2
15
5
5
5
5
]
Receive Q Channel Offset Register
where: D
Receive Data Access Points
Receive I Channel Data Access Point
Receive Q Channel Data Access Point
Receive Q channel offset [15:8]
Receive Q channel offset [7:0]
Receive channel data [15:8]
Receive channel data [7:0]
40
4
4
4
4
D
N
out
in
off
is the signal input, and
is the value in the register.
is the signal output.
3
3
3
3
2
2
2
2
1
1
1
1
0
0
0
0
CMX981
D/981/1