TPU2735 Просмотр технического описания (PDF) - Unspecified

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производитель

TPU2735

Teletext Processor

Unspecified 

TPU 2735

7.2. The Page Selection Register, R-PS

The CCU can write a number of a page into R-PS when

this page has been requested before and shall now be

displayed. R-PS has only effect if SIC = 1. (see section

9., “Two Ways to Select a Page for Display”).

R-PS Page Selection Register

address 0/24/16, 2-byte register

D7 D6

D5 D4 D3 D2 D1 D0

*

TXID OPN DPC FLOF OE

D7 D6

magazine number

(binary, 0 0 0¢8)

D5 D4 D3 D2 D1 D0

tens BCD

units BCD

page number selected for display

TXID:

Teletext transmission indicator

TXID = 1 if a Teletext line was detected in the vertical

flyback interval.

OPN:

open

OPN = 1 makes the TPU receive a requested page

whenever it is transmitted. OPN = 0 makes the TPU re-

ceive a requested page only if NRF = 1, or errors have

been detected (ERF = 1), or C4 = 1 or C8 = 1 (clear

page or update page).

DPC:

disable parity checking

DPC = 1 disables parity checking for the data bytes of all

received TTX rows.

FLOF:

enable FLOF mode

FLOF = 1 enables reception of rows 24, 27 and 8/30.

OE:

odd/even data sampling

OE = 0 samples the odd data bits off the D2DATA signal,

OE=1 samples the even data bits. This bit is used to se-

lect the TTX Data channel for DMAC VBI TTX Data.

7.3. The Subcode Register, R-SC

The subcode register can be used to make the TPU

2735 respond only to transmitted pages with the sub-

code specified in R-SC. The subcode is normally inter-

preted as a time code.

R-SC Subcode Register

address 0/24/18, 2-byte register

D7 D6

D5 D4 D3 D2 D1 D0

SSC0 SCT2 SCT1 SCT0 SCU3 SCU2 SCU1 SCU0

SCT:

subcode tens (minutes tens)

SCU:

subcode units (minutes units)

D7 D6

D5 D4 D3 D2 D1 D0

SSC2 SSC1 SCM1 SCM0 SCH3 SCH2 SCH1 SCH0

SC:

subcode control

SCM:

subcode thousands (hours tens)

SCH:

subcode hundreds (hours units)

The subcode-control flags SCC 0 to SCC 2 determine

for which sector the subcode is valid.

Subcode Control Flags

SSC2

0

0

0

0

1

1

1

1

SSC1

0

0

1

1

0

0

1

1

SSC0

0

1

0

1

0

1

0

1

Function

subcode ignored

subcode valid only for sector 1

subcode valid only for sector 2

subcode valid only for sector 3

subcode valid only for sector 4

subcode valid only for sector 5

subcode valid only for sector 6

subcode valid for all sectors

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