3.1 Waveform Capture

Before enabling waveform capture, the registers must be set correctly:

CAPTURE_SOURCE:

0 = Capture 16 KHz data for ADC [sQ1.30]

1 = Capture 4 KHz FBW data [sQ2.29] (Full BandWidth = fundamental + harmonics)

2 = Capture 4 KHz NBW data [sQ2.29] (Narrow BandWidth = fundamental only)

3 = Capture 8 KHz FBW data [sQ2.29] (Full BandWidth = fundamental + harmonics)

CAPTURE_TYPE:

0 = One-shot Capture Mode

1 = Continuous Capture Modes

One-shot capture mode is recommended for general purposes; otherwise, the captured data in capture buffer may be not continuous.

CH_SEL_Ix/Vx (x = A, B, C, N for Ix, x = A, B, C for Vx): Capture Channel Select

Up to 7 channels of data may be captured at the same time. These registers are used to appoint which channels will be captured.

CAPTURE_ADDR:

This register is used to specify the starting address of the waveform capture buffer and is interpreted as a pointer to the 32-bit unsigned integer. The waveform capture buffer must be allocated in core 0 memory spaces.

CAPTURE_BUFF_SIZE:

This register specifies the buffer size in units of DWORD for capture function. It must be divisible by the number of channels selected. The buffer size must not be larger than the allocated size, otherwise, the application code may be corrupted by a buffer overrun.

After all these registers are set correctly, the user can enable the waveform capture function by setting CAPTURE_EN to 1. Check CAPTURE_STATUS to get capture status.

Here are the capture buffer distribution samples: