PIN DESCRIPTION

Pin

Symbol

Function

Description

+5V

Positive supply voltage

2,3,40 *

A11, A12, A10

Chapter address

Address selection outputs for 1 of 8 external static

RAM chapters each of 1 kBytes.

4 *

OE

Output enable

Active-low external static RAM output enable control

signal.

5 *

WE

Write enable

Active-low external static RAM write enable control

signal. It supports write-cycles interleaved with

read-cycles.

6

TTD

Teletext data input

An A.C. coupled teletext data input supplied by the

µs

after each TV line.

7

TTC

Teletext clock input

A 6.9375MHz clock signal, supplied by the SAA5231

chip, is internally A.C. coupled, clamped and

buffered.

8

ODD/EVEN

Interlaced mode state output

High for even numbered and low for odd-numbered

frames. The value is valid 2

µs before the end of

lines 311 and 624.

9

F6

Character display clock signal

The 6MHz clock signal, supplied by the SAA5231

chip is internally A.C. coupled, clamped and buffered.

10

VCS

Video composite

synchronization input signal

Active high VCS input.

11

SAND

Sandcastle

Three level output pulse to the SAA5231 device.

Phase lock, blanking signal, and color burst

components are contained in this signal.

12

TCS/SCS

Input / output composite

synchronization signal

Scan composite input signal (SCS) for the display

synchronization or Text composite sync. (TCS)

output signal to the SAA5231. Both signals are

active low.

13,14,15

R G B

Red, green, blue

Character and background colors active-high

open-drain outputs.

16

COR

Contrast reduction

Open-drain active-low output supporting optimal

display of characters in ”mixed mode” operation.

17

BLAN

Blanking signal output

Open-drain active high output for TV-image blanking

in normal and mixed-mode operation.

18

Y

Foreground output

Open-drain active-high output with foreground

information. Can be used for printer command.

19

SCL

Serial clock

Microprocessor clock input via serial bus.

20

SDA

Serial data input / output

Open-drain microprocessor serial data input/output

via serial bus.

21

0 Volt

Ground.

22-29 *

D0-D7

Parallel data input / output

Eight tri-state input/output for data read/write from/to

an external static RAM.

30-39 *

A0-A9

Address signals

Ten addresses output pins for accessing to

individual Bytes of a 1 kByte chapter stored in an

external Static RAM.

* Pins only activated when 8KBytes of external memory are addressed, otherwise pins OE and WE remain high, and others remain low.

STV5345 - STV5345/H - STV5345/T

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