Broadcom 公司的BCM7405是高性能高清晰度（HD）卫星电视，有线电视和IP机顶盒（STB）DVR片上系统解决方案。它包括有快速1000-DMIPS IPS32/MIPS16e™级的CPU，高速图像处理，一个非常灵活的数据传输处理器，一个和MPEG-4/VC-1/MPEG-2兼容的视频译码器，一个可编程音频译码器，六个视频DAC以及立体声高保真音频DAC，两个快速以太网端口，一个集成的PHY，三个USB 2.0，一个PCI 2.3/Expansion 总线，高速400MHz DDR2存储器控制器以及能提供各种STB控制功能的外设控制器，是STB应用中性能最高的单片系统。本文介绍了BCM7405的主要性能，方框图以及采用BCM7405的HD STB系统方框图。

BCM7405
Multi-Format HD Digital Video/Audio SOC for Satellite, IP and Cable DVR STBs with Watch-and-Record DVR

The BCM7405 is a high-performance, high definition (HD) satellite, cable, and IP set-top box DVR System-on-Chip solution. It combines a fast 1000-DMIPS MIPS32/MIPS16e™-class CPU, high-speed graphics processing, including video scaling and motion adaptive deinterlacing, a very flexible data transport processor, an MPEG-4/VC-1/MPEG-2/AVS-compliant video decoder, a programmable audio decoder, six video DACs, stereo high-fidelity audio DACs, dual Fast Ethernet ports, one with integrated PHY, triple USB 2.0, a PCI 2.3/Expansion Bus, a high-speed 400-Mhz DDR2 memory controller, and a peripheral control unit that provides a variety of set-top box control functions. Integrated in 65- nm technology, it offers one of the highest levels of single-chip system performance available for STB applications.

The MPEG-2 DVB-compliant transport stream/PES parser and demultiplexer is capable of simultaneously processing 256 PIDs via 128 PID channels in up to six independent external transport stream inputs and two internal playback channels. All 128 PID channels can be used by the record, audio, and video interface engine (RAVE), PCR processing, message filter, and output via the high-speed transport or remux module. The data transport module can be configured to support eight record channels for PVR functionality and six A/V channels to interface to audio and video decoders.

The transport provides 1DES/3DES/DVB/Multi2/AES descrambling support. A memory-to-memory DMA security module may be programmed for  AES/1DES/3DES/CSS/CPRM/CPPM/DTCP copy protection algorithms/standards. The BCM7405 features the Broadcom Secure Processor (BSP), providing secure key generation, management, and protection. The BSP also supports downloadable security A new video decoder is featured in the BCM7405 that is capable of simultaneous decode of an HD and SD stream with picture-in-picture display. Other Mosaic or tiled stream combinations can also be supported for an enhanced video-rich navigation user experience. DivX 3.11/4.11/ 5.x and MPEG-4 Part 2 Simple profile and Advanced Simple profile at Level 5 are additionally supported.

The BCM7405 has an advanced audio processor capable of decoding a wide range of digital audio formats. This audio decoder also supports a number of popular transcoding operations such as AAC to DTS 5.1 or AC3+ to AC3.

The BCM7405’s video and graphics processing features significantly improved scaling and blending performance, enabling real-time video-like graphics effects to be implemented. Digital contour reduction improves the video quality of low-bit-rate AVC/AVS video. An ITU-R- 656 output port is also provided with a teletext sideband. The 1000-DMIPS MIPS32™ CPU has been designed to maximize overall system performance and has significantly improved cache performance over previous-generation devices. The CPU subsystem also includes a Floating Point Unit.

Integrated peripherals include three UARTS, dual ISO7816 SmartCard interfaces, counter/timers, GPIO ports, a LED/keypad controller, IR receivers, an IR blaster, a UHF remote control receiver, an integrated soft modem system side device, and serial controllers.

主要特性：
Advanced multi-format decoder supporting the following:
HD/SD H.264/AVC Main and High Profile to Level 4.1 (HD), Level 3.1 (SD)
HD/SD AVS Jizhun Profile Levels 2.0, 4.0, and 6.0 (720p and 1080i for HDTV)
VC-1 Advanced Profile @ Level 3, Simple and Main Profile
HD/SD MPEG-2 Main Profile at Main and High levels
MPEG still image decode
SD MPEG-4 P2 SP/ASP
HD DivX 3.11/4.11/5.x/6x/Home Theater
Advanced audio processor supporting the following:
AAC LC, AAC LC+SBR Level 2, AAC+ Level 2, AAC-HE
Dolby® Digital, Dolby Digital Plus
MPEG I layers 1, 2, and 3 (MP3)
Windows Media®and Windows Media Pro audio
One pair of on-chip stereo high-fidelity audio DACs
3D SRS audio support
One I2S input port and one I2S output port, plus S/PDIF output
High-performance 2D-effects graphic engine
Studio-quality text and graphics at HD resolution
Supports multiple layers and windows
Digital noise and contour reduction (DNR/DCR)
Reduces artifacts such as block/mosquito noise
Picture-in-picture
Supports simultaneous HD+SD display
Mosaic Mode
Supports up to 16 video decode/display for video-rich navigation
Motion-adaptive deinterlacer with reverse 3:2/2:2 pulldown
OpenCable ready with on-chip MPOD support
400-MHz Dual-Core CMT MIPS32®/16e class processor
64-bit DDR2 DRAM controller
Dual SATA-2 interfaces for DVR and DVD applications
HD analog video encoder with simultaneous SD outputs
NTSC-M/J, PAL-BDGHIN/M/Nc, SECAM analog outputs
480i/480p/576i/576p/720p/1080i output formats
Component RGB/YPrPb HD/HD-DVO outputs
Macrovision® 7.1/NICAM support
SCART 1 and 2
Component, S-Video, and composite via six on-chip V-DACs
VBI encoders for CC/TTX with NABTS/CGMSA/WSS/ Gemstar®, AMOL I/II standards and dedicated TTX sideband
RF modulator with BTSC encoder
ITU-R-656 input and output ports
HDMI 1.3/DVI 1.0 Mac and PHY with HDCP 1.1
Broadcom security processor
AES/1DES/3DES/CSS/CPRM/DTCP copy protection
MPEG-2/DIRECTV/DVB/ARIB data transport demux with 1DES/3DES/DVB/Multi2/AES descramblers
V.92-capable soft modem with integrated SiLab Si305x system side device
Dual USB 2.0 host controller with host transceiver
Additional host/client USB 2.0 controller/transceiver
Dual Ethernet MACs with integrated single PHY and MII
UHF remote control receiver
Dual SmartCard support



图1.BCM7405方框图



图2.BCM7405 HD STB系统方框图