SAA5290A Philips Semiconductors, SAA5290A Datasheet - Page 32

• Manufacturer Part Number: SAA5290A
• Description: Economy teletext and TV microcontrollers
• Manufacturer: Philips Semiconductors

Philips Semiconductors
8.7
If the TXT0.INV ON bit is a logic 1, memory block 8 is used
as an inventory page.The inventory page consists of two
tables: the Transmitted Page Table (TPT) and the Subtitle
Page Table (SPT).
In each table, every possible combination of the page tens
and units digit, 00H to FFH, is represented by a byte. Each
bit of these bytes corresponds to a magazine number so
1997 Jul 07
handbook, full pagewidth
Economy teletext and TV microcontrollers
Inventory page
Bytes in each byte
Bytes in the table
row n
n + 1
n + 6
n + 7
column
0
8
7xx
bit
7
6xx
Fig.8 Table organisation.
5xx
16
4xx
32
each page number, from 100 to 8FF, is represented by a
bit in the table.
The bit for a particular page in the TPT is set when a page
header is received for that page. The bit in the SPT is set
when a page header for the page is received which has the
‘subtitle’ page header control bit (C6) set.
Before the inventory page is enabled the software must
ensure that page request 8 is put on hold.
3xx
24
2xx
1xx
8xx
0
32
SAA5x9x family
Preliminary specification
MGD160
39