10.3.4.45 ATPL360_REG_RRC_NOTCH_INDEX (0x4025)
Array of RRC notch filter index values. There is one index for each notched frequency. The format of each index is sQ8.7. The 9 integer bits (including sign bit) indicate the carrier index [-256-255] for which the notch filter is applied. The 7 decimal bits can apply the notch filter to a frequency that is between two consecutive carriers.
To convert the notch index to a frequency (in Hz), the following formulas are applied,
depending on the number of channels used (ATPL360_REG_NUM_CHANNELS (0x403D)):
- Single Channel: F = INDEX * k + 65429.6875 + (Ch – 1) * 54687.5
- Double Channel: F = INDEX * k + 92773.4375 + (Ch – 1) * 54687.5
- k = 1000000 / (2048 * 128) = 3.814697265625 Hz
- Ch: PRIME channel used [1-8] (ATPL360_REG_CHANNEL_CFG (0x4016))
For example:
- Single Channel 1, INDEX = -768 (0xFD00): F = -768 * k + 65429.6875 = 62500 Hz
- Double Channel 3&4, INDEX = 16 (0x0010): F = 16 * k + 92773.4375 + 2 * 54687.5 = 202209 Hz
Access: Depends on noise analyzer mode (ATPL360_REG_ENABLE_AUTO_NOISE_CAPTURE
(0x4021)):
- Auto-mode (1): Read-only
- Manual-mode (0): Read-write
Value Range: 10 bytes. The number of valid 2-byte words depends on the number of notched frequencies (ATPL360_REG_RRC_NOTCH_ACTIVE (0x4024)).
Default Value: All 0s.