Ic Description; Teletext Decoder With Embedded 8-Bit Controller; Block Diagram Of The Sda55Xx; Description - Daewoo DTH-29U3 Service Manual

4 IC DESCRIPTION

4.1 TELETEXT DECODER WITH EMBEDDED 8-BIT CONTROLLER

TVText Pro is a 8-bit controller based on a enhanced 8051 core with embedded teletext, On screen Display and TV
controller functions.

4.1.1 BLOCK DIAGRAM OF THE SDA55XX

4.1.2 DESCRIPTION

The SDA 55xx is a single chip teletext decoder for decoding World System Teletext data as well as Video
Programming System (VPS), Program Delivery Control (PDC), and Wide Screen Signalling (WSS) data used for PAL
plus transmissions (line 23).
The device provides an integrated general-purpose, fully 8051-compatible Microcontroller with television specific
hardware features. The microcontroller has been enhanced to provide powerful features such as memory banking,
data pointers and additional interrupts etc.
The on-chip display unit for displaying Level 1.5 teletext data is also used for customer defined on-screen displays.
Internal XRAM consists of 16 Kbytes. Device has an internal ROM of 128 Kbytes.
The SDA 55xx supports a wide range of standards including PAL, NTSC and contains a digital slicer for VPS, WSS,
PDC, TTX and Closed Caption, an accelerating acquisition hardware module, a display generator for Level 1.5 TTX
data and powerful On screen Display capabilities based on parallel attributes, and Pixel oriented characters (DRCS).
The 8-bit Microcontroller runs at 360 ns. cycle time (min.). Controller with dedicated hardware does most of the
internal TTX acquisition processing, transfers data to/from external memory interface and receives/transmits data via I
2 C-firmware user-interface. The slicer combined with dedicated hardware stores TTX data in a VBI buffer of 1
Kilobyte. The Microcontroller firmware performs all the acquisition tasks (hamming-and parity-checks, page search
CP830F Service Manual
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