• Other camera modules can be supported as long as they provide the same signal timing.
5 Function description
5.1 Camera interface engine
There is a dedicated processor in LPC55S69 which can handle the signals of camera.
It reads the data from camera and stores the data in the RAM which is accessed by Arm core. Before using dedicated processor,
some configurations must be made, which includes pin configuration, clock enable, dedicated processor enable, interrupt enable
and so on.
5.2 Camera driver library
The instructions of dedicated processor use the type of machine code. The code implements the function of camera interface
protocol and is released in lib. Some API routines are provided in this application. User can use API routines to initialize the engine
and configure the pins.
5.3 LCD display
The application note uses LCD to display the video stream from camera in real time. The high-speed SPI port is used for LCD
driving port. The max speed on the SPI bus is 50 Mbit/s, so it can display the 320 × 240 resolution LCD up to 30 fps.
5.4 System clock
The camera engine shares the system clock with Arm
®
core. To speed up the processing time, the system clock must be
configured to 150 MHz. For those below 150 MHz, such as, 96 MHz system clock part, reduce the frequency of pixel clock.
5.5 Clock source of camera
The camera needs a 50 MHz clock source which is provided by CLKOUT signal from MCU.
5.6 I
2
C interface
The camera is configured through I
2
C interface which can be connected with I
2
C peripheral port in the MCU.
5.7 Memory usage
The 320 × 240 resolution picture requires 150 K bytes RAM space. The solution uses the space address from
0x20010000
to
0x20035800
.
Additionally, the instruction code of camera engine must run in the RAM for high performance. This solution uses the space
address from
0x20040000
to
0x20043FFF
to store camera engine code.
5.8 Other supported camera modules
Other camera modules can be supported as long as they provide the same signal timing.
1. The camera module must be configured as RGB565 mode with the timing diagram, as shown in
.
NXP Semiconductors
Function description
Camera Interface in LPC55(S)xx, Rev. 3, 07 September 2021
Application Note
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