Figure 1-2. ST9294 Block Diagram

CPU

16-Bit TIMER / WATCHDOG + SPI

SLICE

TIMER

256 Bytes

REGISTER FILE

DATA

SLICER

CC Video

I/O PORT 0

8

384 / 640 Bytes

RAM

12k / 24k Bytes

ROM

I/O PORT 3

7

ON SCREEN

DISP LAY

PLL

HSYNC

PLLR

PLLF

AV

DD

VSYNC

I/O PORT 4

P.W.M.

O utputs

8

P.W.M.

D/ A

CONVERTER

I/O PORT 2

( Analog Inputs )

6

A/ D

CONVERTER

I/O PORT 5

( SPI )

2

MEMORY BUS ( Address & Data )

REGISTER BUS ( Address & Data )

VR0A1749

Note : 42 SDIP shown

1.1 GENERAL DESCRIPTION

The ST9294 is a ROM member of the ST9 family of

microcontrollers, completely developed and pro-

duced by SGS-THOMSON Microelectronics using

a proprietary n-well HCMOS process.

The ROM parts are fully compatible with their

EPROM versions, which may be used for the pro-

totyping and pre-production phases of develop-

ment.

The nucleus of the ST9294 is the advanced Core

which includes the Central Processing Unit (CPU),

the Register File, a 16-bit Timer/Watchdog with 8-

bit Prescaler, a Serial Peripheral Interface support-

ing S-bus, I

8-bit I/O ports. The Core has independent memory

and register buses allowing a high degree of pipe-

lining to add to the efficiency of the code execution

speed of the extensive instruction set.

The powerful I/O capabilities demanded by micro-

controller applications are fulfilled by the ST9294

with up to 31/42 I/O lines dedicated to digital In-

put/Output. These lines are grouped into up to six

I/O Ports and can be configured on a bit basis un-

der software control to provide timing, status sig-

nals, timer inputs and outputs, analog inputs, ex-

ternal interrupts and serial or parallel I/O.

Three basic memory spaces are available to sup-

port this wide range of configurations: Program

Memory, Data Memory and the Register File,

which includes the control and status registers of

the on-chip peripherals.

The 16-bit Slice Timer with an 8-bit Prescaler.

The human interface is provided by the On Screen

Display module, this can produce up to 15 lines of

up to 34 characters from a ROM defined 128 char-

acter set. The 9x13 character can be modified by 4

different pixel sizes, with character rounding, and

formed into words with colour and format attrib-

utes.

Closed Caption control for the display of informa-

tion transmitted through the video input is facili-

tated with the Data Slicer. This module has manual

and automatic Slicing levels for both Sync and

Data and allows the user to select the video line

containing the data relative to the Vertical synchro-

nisation pulse.

®

ST9294

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