Sony CXD5602 User Manual page 963

When the end of operation is notified (when a parameter ADC_PROPERTY.*_ENABLE in the SCU_RAM is
changed from "1" to "0"), the ADC reads out the corresponding data of SCU_ADCIF_FIFO until the FIFO
becomes EMPTY, then discards them. The function is prepared so that unnecessary data cannot be read out even
if the ADC is rebooted without resetting the SCU_ADCIF_FIFO.
The sample of the HPADC is processed every eight samples at a time. Accordingly, the time stamp per sample
cannot be recorded correctly. The fluctuation of the time stamp when eight samples are processed at a time can be
minimized by making the number of the DMA's Watermark multiple of the eight samples. However, the
following fluctuation will occur if the samples are written during time stamp's reading out even when making the
number of the DMA's Watermark multiple of the eight samples.
(The remaining number of the 8-FIFO data%8) × (INTERVAL[sec]－165/scu_clock_freq[Hz])
In this formula, INTERVAL means sample's interval (second).
3.21.9 Gain Control
3.21.9.1 Gain Control of the LPADC
The LPADC has a fixed voltage range, there is no gain control. Input the data with appropriate signal level based
on the LSI's specifications, and perform appropriate signal processing after importing the data.
3.21.9.2 Gain Control of the HPADC
Gain control of the HPADC is performed in registers LV_LPFn_ATT_SEL, LV_LPFn_GAIN1ST, and
LV_LPFn_GAIN2ND (n = 0,1).
Function Name
LPF
Gain setting
-6dB
0dB
6dB
12dB
14dB
The combinations of setting other than the setting listed in Table ADC-817 are prohibited. Use the designated
combinations of setting.
The following describes gain control overview.
Table ADC-777 Gain Control of the HPADC
Control Register Name (n = 0, 1)
LV_LPFn_ATT_SEL
2'b10
2'b00
2'b00
2'b00
2'b00
－963/1010－
LV_LPFn_GAIN1ST
4'b0000
4'b0000
4'b0100
4'b1100
4'b0100
CXD5602 User Manual
LV_LPFn_GAIN2ND
4'b0000
4'b0000
4'b0000
4'b0000
4'b1000