SBAS774B May 2016 – December 2021 ADC32RF80 , ADC32RF83
PRODUCTION DATA
In this detector mode the peak power is computed for a block of N samples over a programmable block length and then compared against two sets of programmable thresholds (with hysteresis).
The RMS power detector circuit provides configuration options, as shown in Figure 8-50. The RMS power value (1 or 2 bit) can be output onto the GPIO pins. In 2-bit output mode, two different thresholds are used whereas the 1-bit output provides one threshold together with hysteresis.
Table 8-11 shows the register configurations required to set up the RMS power detector. The detector operates in the fS / 8 clock domain. The AGC modes can be configured separately for channel A (54xxh) and channel B (5Cxxh), although some registers are common in 54xxh (such as the GPIO pin selection).
REGISTER | ADDRESS | DESCRIPTION |
---|---|---|
RMSDET EN | 5420h, 5C20h | Enables RMS detector |
PWRDETACCU | 5421h, 5C21h | Programs the block length to be used for RMS power computation. The block length is defined in terms of fS / 8 clocks. The block length can be programmed as 2M with M = 0 to 16. |
PWRDETH, PWRDETL | 5422h, 5423h, 5424h, 5425h, 5C22h, 5C23h, 5C24h, 5C25h | The computed average power is compared against these high and low thresholds. One LSB of the thresholds represents 1 / 216. For example: is PWRDETH is set to –14 dBFS from peak, [10(–14 / 20)]2 × 216 = 2609, then set 5422h, 5423h, 5C22h, 5C23h = 0A31h. |
RMS2BIT EN | 5427h, 5C27h | Enables 2-bit output format for the RMS detector output. |
OUTSEL GPIO[4:1] | 5432h, 5433h, 5434h, 5435h | Connects the PWRDET alarms to the GPIO pins; common register. |
IODIR | 5437h | Selects the direction for the four GPIO pins; common register. |
RESET AGC | 542Bh, 5C2Bh | After configuration, reset the AGC module to start operation. |