CMX991 Datasheet, PDF (30/56 Pages) CML Microcircuits – Two-mode demodulator

RF Quadrature Transceiver / RF Quadrature Receiver
CMX991/CMX992
b3 b2 b1 b0
0
01
0 VGA = -12dB
0
00
1 VGA = -6dB
0
00
0 VGA = 0dB (Maximum gain)
6.4.2 Rx Mode Register:
8-bit read-only
C-BUS address $E3
This read-only register mirrors the value in register $13; see section 6.4.1 for details of bit functions.
6.5 Tx Control Register (CMX991 only)
6.5.1 Tx Control Register: C-BUS address $14
8-bit write-only
This register controls transmitter features including Powersave modes.
All bits of this register are cleared to ‘0’ by a General Reset command.
Bit:
7
6
5
4
3
2
0
TxMix Pwr
0
I/Q Mod
0
0
Pwr
1
Freq
0
I/Q Out
Tx Control Register b7 - b4
These bits control power up/power down of the various blocks of the IC.
In all cases ‘1’ = power up, ‘0’ = power down.
b7
Reserved set to ‘0’
b6
Enable image-reject up-converter
b5
Reserved set to ‘0’
b4
Enable I/Q modulator, filters and its input circuits
Tx Control Register b3 and b2
Reserved set to ‘0’.
Tx Control Register b1
Controls internal operating mode for LO circuits, set b1 = ’0’ for frequency below 600MHz;
set b1 = ’1’ for frequencies above 600MHz.
Tx Control Register b0
With b0 = ’0’ the output of the I/Q modulator is connected to the image-reject up-converter;
with b0 = ’1’ the output of the I/Q modulator is connected to the TXIFOUT output pin.
6.5.2 Tx Control Register C-BUS address $E4
8-bit read-only
This read-only register mirrors the value in register $14; see section 6.5.1 for details of bit functions.
 2015 CML Microsystems Plc
30
D/991_992/20