Texas Instruments 3138 155 232931 - Manual (Page 74)

CC2420
SWRS041B Page 74 of 89
MANAND (0x21) - Manual signal AND override register
1
Bit Field Name Reset R/W Description
15 VGA_RESET_N 1 R/W The VGA_RESET_N signal is used to reset the peak detectors in
the VGA in the RX chain.
14 BIAS_PD 1 R/W Global bias power down (1)
13 BALUN_CTRL 1 R/W The BALUN_CTRL signal controls whether the PA should
receive its required external biasing (1) or not (0) by controlling
the RX/TX output switch.
12 RXTX 1 R/W RXTX signal: controls whether the LO buffers (0) or PA buffers
(1) should be used.
11 PRE_PD 1 R/W Powerdown of prescaler.
10 PA_N_PD 1 R/W Powerdown of PA (negative path).
9 PA_P_PD 1 R/W Powerdown of PA (positive path). When PA_N_PD=1 and
PA_P_PD=1 the up-conversion mixers are in powerdown.
8 DAC_LPF_PD 1 R/W Powerdown of TX DACs.
7 XOSC16M_PD 1 R/W
6 RXBPF_CAL_PD 1 R/W Powerdown control of complex bandpass receive filter calibration
oscillator.
5 CHP_PD 1 R/W Powerdown control of charge pump.
4 FS_PD 1 R/W Powerdown control of VCO, I/Q generator, LO buffers.
3 ADC_PD 1 R/W Powerdown control of the ADCs.
2 VGA_PD 1 R/W Powerdown control of the VGA.
1 RXBPF_PD 1 R/W Powerdown control of complex bandpass receive filter.
0 LNAMIX_PD 1 R/W Powerdown control of LNA, down-conversion mixers and front-
end bias.
1 For some important signals the value used by analog and digital modules can be overridden manually. This is done
as follows for the hypothetical important signal IS:
IS_USED = (IS * IS_AND_MASK) + IS_OR_MASK,
using boolean notation.
The AND-mask and OR-mask for the important signals listed resides in the MANAND and MANOR registers,
respectively.
Examples:
• Writing 0xFFFE to MANAND and 0x0000 to MANOR will force LNAMIX_PD ≡0 whereas all other signals will be
unaffected.
• Writing 0xFFFF to MANAND and 0x0001 to MANOR will force LNAMIX_PD ≡1 whereas all other signals will be
unaffected.