CMX980AL7 CML Microcircuits, CMX980AL7 Datasheet - Page 68

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

TETRA Baseband Processor
Title:
Address:
Function:
Description:
7:0
7:1
7:0
7:1
Bit
0
0
1999 Consumer Microcircuits Limited
TxIPhaseLSB
TxIPhaseMSB
TxQPhaseLSB
TxQPhaseMSB
TxPhase
Transmit I and Q channel Phase correction register
$0x40, $0x41, $0x46, $0x47 (4 locations)
RW
This register controls the Tx Data path I and Q channel phase compensation. The phase may
be adjusted by 7.1 with respect to the input data signal phase. As each channel has separate
phase adjustments the maximum differential phase compensation that can be achieved is
The amount of phase adjustment applied is given by the formula:
Note: Although each channel is separately adjustable with its own compensation value, the
effect of phase adjustment is only detectable by measuring the phase angle between I and Q
channels. It should be noted that the N
positive values of N
channel for positive values of N
example, putting the value 10 (decimal) into both TxIPhase and TxQPhase would produce a
differential phase on I and Q of:
Name
14.2 . The phase adjustment value written to this register is a 2s-complement value (N
Address $0x40
Address $0x41
Address $0x46
Address $0x47
tan
Data
Data
Data
Data
- 1
Active State
N
phase
2
11
RW
RW
RW
RW
RW
RW
(conversely, leading the phase for negative values) and leading the Q
Least significant 8 bits of the TxIPhase register (N
Reserved. Set these bits Low. Undefined on read.
Most significant bit of the TxIPhase register (sign bit).
Least significant 8 bits of the TxQPhase register (N
Reserved. Set these bits Low. Undefined on read.
Most significant bit of the TxQPhase register (sign bit).
90
Where:
phase
o
- 2(tan
68
(conversely, lagging the phase for negative values). For
phase
-1
N
(4.88x10
value has the effect of lagging the I channel for
phase
-3
)) = 89.44
is the phase adjustment,
is the value in the register and has
a range of -256 to +255.
Function
o
phase
phase
CMX980A
D/980A/3
).
).
phase
).