TriMedia overview - pnx1300 peripherals

The TriMedia pnx1300 and cs1300 System on Chip devices have three independent processors, and five sets of I/O peripherals. One of the processors is the core TriMedia CPU: the other two are an Image Co-Processor and a Variable Length Decoder. The I/O peripherals support audio, video, serial, PCI and I2C communications.

The Image Co-Processor implements image scaling and filtering, overlay with alpha blending and chroma keying, and changing image data formats. The Variable Length Decoder is dedicated to Huffman decoding (important for MPEG).

The video in and out peripherals handle CCIR 656/601 digital video data. They can also be used at up to 80 Mbyte/s for raw 8 or 10 bit data. The video peripherals also support video image scaling and filtering, and video image overlay with alpha blending.

Audio input is through a versatile serial interface that allows matching to any serial audio ADC and DAC - the serial format can be programmed with control of the word length and position of data within the word. Audio output can be up to 8 channels - this is for handling multi channel surround sound, for instance in Dolby Digital AC-3 format which involves six loudspeakers.

The PCI interface allows passing of video data, for instance direct to graphics display cards. It also supports inclusion of TriMedia into systems (such as set-top boxes) that are based on the PCI bus as a convenient system interconnect.

A synchronous serial interface is designed primarily for connection to telephony devices such as a V.34 modem. It can also be used, for example, to interface to other telecomms serial formats such as ISDN. The I2C interface is a simple serial bus for control data: on the TriMedia IREF board, for example, this is used to control the video codecs to select PAL or NTSC video formats. I2C is used in many chips for devices such as remote controls.