BSM=B_0x0, EDM=B_0x0, PCKPOL=B_0x0, CAPTURE=B_0x0, FCRC=B_0x0, ENABLE=B_0x0, OEBS=B_0x0, CROP=B_0x0, HSPOL=B_0x0, JPEG=B_0x0, CM=B_0x0, ESS=B_0x0, LSM=B_0x0, VSPOL=B_0x0, OELS=B_0x0
DCMI control register
| CAPTURE | Capture enable The camera interface waits for the first start of frame, then a DMA request is generated to transfer the received data into the destination memory. In snapshot mode, the CAPTURE bit is automatically cleared at the end of the first frame received. In continuous grab mode, if the software clears this bit while a capture is ongoing, the bit is effectively cleared after the frame end. Note: The DMA controller and all DCMI configuration registers must be programmed correctly before enabling this bit. 0 (B_0x0): Capture disabled 1 (B_0x1): Capture enabled |
| CM | Capture mode 0 (B_0x0): Continuous grab modeThe received data are transferred into the destination memory through the DMA. The buffer location and mode (linear or circular buffer) is controlled through the system DMA. 1 (B_0x1): Snapshot mode (single frame)Once activated, the interface waits for the start of frame and then transfers a single frame through the DMA. At the end of the frame, the CAPTURE bit is automatically reset. |
| CROP | Crop feature 0 (B_0x0): The full image is captured. In this case the total number of bytes in an image frame must be a multiple of four. 1 (B_0x1): Only the data inside the window specified by the crop register is captured. If the size of the crop window exceeds the picture size, then only the picture size is captured. |
| JPEG | JPEG format 0 (B_0x0): Uncompressed video format 1 (B_0x1): This bit is used for JPEG data transfers. The DCMI_HSYNC signal is used as data enable. The crop and embedded synchronization features (ESS bit) cannot be used in this mode. |
| ESS | Embedded synchronization select Note: Valid only for 8-bit parallel data. HSPOL/VSPOL are ignored when the ESS bit is set. This bit is disabled in JPEG mode. 0 (B_0x0): Hardware synchronization data capture (frame/line start/stop) is synchronized with the DCMI_HSYNC/DCMI_VSYNC signals. 1 (B_0x1): Embedded synchronization data capture is synchronized with synchronization codes embedded in the data flow. |
| PCKPOL | Pixel clock polarity This bit configures the capture edge of the pixel clock. 0 (B_0x0): Falling edge active 1 (B_0x1): Rising edge active |
| HSPOL | Horizontal synchronization polarity This bit indicates the level on the DCMI_HSYNC pin when the data are not valid on the parallel interface. 0 (B_0x0): DCMI_HSYNC active low 1 (B_0x1): DCMI_HSYNC active high |
| VSPOL | Vertical synchronization polarity This bit indicates the level on the DCMI_VSYNC pin when the data are not valid on the parallel interface. 0 (B_0x0): DCMI_VSYNC active low 1 (B_0x1): DCMI_VSYNC active high |
| FCRC | Frame capture rate control These bits define the frequency of frame capture. They are meaningful only in Continuous grab mode. They are ignored in snapshot mode. 0 (B_0x0): All frames are captured. 1 (B_0x1): Every alternate frame captured (50% bandwidth reduction) 2 (B_0x2): One frame out of four captured (75% bandwidth reduction) |
| EDM | Extended data mode 0 (B_0x0): Interface captures 8-bit data on every pixel clock. 1 (B_0x1): Interface captures 10-bit data on every pixel clock. 2 (B_0x2): Interface captures 12-bit data on every pixel clock. 3 (B_0x3): Interface captures 14-bit data on every pixel clock. |
| ENABLE | DCMI enable Note: The DCMI configuration registers must be programmed correctly before enabling this bit. 0 (B_0x0): DCMI disabled 1 (B_0x1): DCMI enabled |
| BSM | Byte Select mode Note: This mode only works for EDM[1:0] = 00. For all other EDM values, this field must be programmed to the reset value. 0 (B_0x0): Interface captures all received data. 1 (B_0x1): Interface captures every other byte from the received data. 2 (B_0x2): Interface captures one byte out of four. 3 (B_0x3): Interface captures two bytes out of four. |
| OEBS | Odd/Even Byte Select (Byte Select Start) This bit works in conjunction with BSM field (BSM different 00). 0 (B_0x0): Interface captures first data (byte or double byte) from the frame/line start, second one being dropped. 1 (B_0x1): Interface captures second data (byte or double byte) from the frame/line start, first one being dropped. |
| LSM | Line Select mode 0 (B_0x0): Interface captures all received lines. 1 (B_0x1): Interface captures one line out of two. |
| OELS | Odd/Even Line Select (Line Select Start) This bit works in conjunction with the LSM field (LSM = 1). 0 (B_0x0): Interface captures first line after the frame start, second one being dropped. 1 (B_0x1): Interface captures second line from the frame start, first one being dropped. |