Browse Prior Art Database

Raster Memory Scannable by Row or by Column

IP.com Disclosure Number: IPCOM000075889D
Original Publication Date: 1971-Dec-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Eiselen, ET: AUTHOR

Abstract

This is a raster scanning technique which includes a memory that may be accessed sequentially in either a horizontal or vertical direction by a simple counter, not shown.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 86% of the total text.

Page 1 of 2

Raster Memory Scannable by Row or by Column

This is a raster scanning technique which includes a memory that may be accessed sequentially in either a horizontal or vertical direction by a simple counter, not shown.

An exemplary memory consists of 16 modules, the address diagram for which is shown. Each module is a 16 x 1 - bit, random access memory, with a 4-bit address being decoded on the module. A module may be selected in either of two ways, one for horizontal access to the memory, and the other for vertical access. The details of how modules are selected are shown in the square labeled "address 0 within module". Thus, by way of example the horizontal scan line 0 is scanned by initially choosing H0 which selects modules 0, 1, 2 and 3 (as shown in Table 1), while the address within the module is set to zero. The scan is completed by accessing addresses-within-module in the sequence 1, 2 and 3. Horizontal scan line 9 is scanned by choosing H1 which selects modules 4, 5, 6 and 7, and accessing the addresses within modules in the sequence 8, 9, 10 and
11. Vertical scanning proceeds in a similar fashion, except the vertical groups of modules are selected, and the addresses within the modules are accessed in a different sequence. For example, to scan vertical column 2, V2 would be selected and the addresses accessed in the sequence 12, 8, 4, 0.

Access is to four modules at one time, thus giving a 4-bit readout whether access is vertical or horizontal.

This techniqu...