IME6400

The IME6400 is a single chip MPEG4/2/1 encoder for audio, video, system. The IME6400 encodes audio/video, multiplex audio and video, and creates MPEG4/2/1 elementary, program and transport streams. The IME6400 is composed of high performance RISC processor core and DSP core with dedicated functional blocks for real-time audio/video applications.

The IME6400 chip performs motion estimation on a wide search area of +/-64H, +/-32V for P pictures and +/-32H, +/-32V for B pictures at half PEL accuracy. The IME6400 supports various motion estimation modes such as frame, field, 16x8 mode for improving compression efficiency.

The IME6400 operation is based on downloadable microcode, thus providing high level of flexibility and ability to create customized solutions per specific applications, such as multi-channel systems. During software initialization, codes are loaded into the internal program memory in one of two ways; either the code is stored in a ROM attached on the external bus, or the code is downloaded from external host. Program memory is extendible by optional external SRAM. To fit into low cost system implementation, IME6400 has internal booting ROM. As the result, the overall video system can be implemented using only one SDRAM and video decoder.

The IME6400 requires external SDRAM for storing video frames, compressed data buffers, and user buffers. The IME6400 supports many SDRAM configurations to meet specific application needs. One 32 bits SDRAM, Two 16 bits SDRAM, four 8 bits SDRAM, eight 4 bits SDRAM configurations are also possible on a 32 bits SDRAM bus. The IME6400 generates all signals required for a glueless interface to SDRAM memory.

The IME6400 video interface is designed to connect directly to digital composite decoders. The industry popular video encoders; Philips SAA7112/SAA7114, Brooktree Bt829A, Samsung KS0127 are supported. It also can directly interface with CMOS image sensor processors for low cost application.

To minimize power consumption, the IME6400 uses multi-clock distribution and clock-gating schemes. The IME6400 has two internal PLLs which provide 54Mhz clocks for core logic, and 81Mhz clocks SDRAM interface logic. The PLL multiplies external 27Mhz clock up to 54Mhz, 81Mhz each.

The IME6400 may be programmed to achieve useful video functions, such as scene change detection, 3 to 2 pull down, variable/constant bit rate control, etc. These powerful features enable IME6400 to be used to the following applications : desktop application, digital video recorders, digital camcorders, recordable DVD, PVR, etc.

The host interface in IME6400 is used to send compressed image data for external host. The interface provides the functionality for applications both in the PC-based platforms or stand-alone systems.