ST92T195 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST92T195

48-96 Kbyte ROM HCMOS MCU WITH ON-SCREEN DISPLAY AND TELETEXT DATA SLICER

STMicroelectronics 

ST92195C/D - TIMING AND CLOCK CONTROLLER

5 TIMING AND CLOCK CONTROLLER

5.1 FREQUENCY MULTIPLIERS

Three on-chip frequency multipliers generate the

proper frequencies for: the Core/Real time Periph-

erals, the Display related time base and the Slicer

over-sampling clock for the Teletext Data slicer.

For both the Core and the Display frequency mul-

tipliers, a 4 bit programmable feed-back counter

allows the adjustment of the multiplying factor to

the application need (a 4 MHz or 8 MHz crystal is

assumed).

Figure 32. Timing and Clock Controller Block Diagram

PXFM

Async.

Handler

MCFM

SLDIV2

Divide

by 2

Frequency

Multiplier

Hsync

Skew Corrector

SKHPLS

SKDIV2

Divide

Synchronized DOTCK / 2 to Display

by 2

(2X Pixel clock for 1X width characters)

SKWEN SKWL(3:0)

4 MHz real time Clock

Frequency

Multiplier

FMEN

FML(3:0)

(Synchronized DOTCK) SKDIV2

Divide

by 2

Divide

by 64

TXCF

Frequency

Multiplier

( x 777 )

SLIEN

to Teletext Display Storage RAM (TRI)

to CSYNC Controller,

SYNC Extractor, ..

48.56 MHz Clock

(Teletext SLicer)

OSCIN

Xtal

Oscillator

OSCOUT

FMEN

FMSL

Divide

by 2

Fimf

Asynch.

Handler

Main Clock Controller

Div-2

Prescaler

1 to 8

Memory Wait

BREQ

WFI

Clock

Control

MODER.5

ST9 Clock Control Unit (RCCU)

CPUCLK

INTCLK

VR02095A

64/249

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