| (19) |
 |
|
(11) |
EP 0 228 745 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
28.03.1990 Bulletin 1990/13 |
| (43) |
Date of publication A2: |
|
15.07.1987 Bulletin 1987/29 |
| (22) |
Date of filing: 18.12.1986 |
|
| (51) |
International Patent Classification (IPC)4: G09G 1/16 |
|
| (84) |
Designated Contracting States: |
|
DE FR GB |
| (30) |
Priority: |
30.12.1985 US 815361
|
| (71) |
Applicant: Philips Electronics N.V. |
|
5621 BA Eindhoven (NL) |
|
| (72) |
Inventors: |
|
- MacKenna, Craig Alden
NL-5656 AA Eindhoven (NL)
- Li, Jan-Kwei Jack
NL-5656 AA Eindhoven (NL)
|
| (74) |
Representative: Strijland, Wilfred et al |
|
INTERNATIONAAL OCTROOIBUREAU B.V.,
Prof. Holstlaan 6
5656 AA Eindhoven
5656 AA Eindhoven (NL) |
|
| |
|
| (54) |
Raster scan video controller provided with an update cache, update cache for use in
such video controller, and CRT display station comprising such controller |
(57) A raster scan video controller is provided with an update cache for selective updating
of a display memory under control of an updating device. The display has a larger
bit width than the updating device. The update cache is full-width connected to the
display memory. Each display memory connection is paired to a corresponding connection
to the updating device. The updating device has random-access facility to the update
cache for accessing only a selective part thereof for receiving, transmitting and
latching data with respect to the update cache. Corresponding functions are available
with respect to the memory.