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APL Program for Automation of Masks for a ROS Array

IP.com Disclosure Number: IPCOM000087396D
Original Publication Date: 1977-Jan-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 61K

Publishing Venue

IBM

Related People

Balasubramanian, PS: AUTHOR [+2]

Abstract

This article describes an APL program called 'PERS' which has been written to automate the design of A, B, and D level masks required by a read-only storage (ROS) array. The "B" mask is generated in accord with user-furnished output words. The program places no restrictions upon word length or array size.

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APL Program for Automation of Masks for a ROS Array

ROS.

This article describes an APL program called `PERS' which has been written to automate the design of A, B, and D level masks required by a read-only storage (ROS) array. The "B" mask is generated in accord with user-furnished output words. The program places no restrictions upon word length or array size.

Physical mask dimensions, e.g., diffusion widths, metal width, gate dimensions, etc., are furnished to the program by the user.

The program output is in the form of a deck of cards in GCL (graphic card language) keypunch language which can readily be converted into GL/1 machine language by IGS (interactive graphic system) or equivalent programs. Additionally, the program informs the user of the load that the array will place upon the decode circuitry, i.e., capacitance of array diffusions and metal areas.

ARRAY ORGANIZATION

The described version of the PERS program will generate an organization, as indicated in Fig. 1. As noted above, the output word may have any number of bits generated in the X dimension. Of course, the user must advise the program of his output word length along with the total number of columns (X dimension) and (Y dimension) in the array. The program checks the word length, X and Y array dimension and the number of input bits to assure that they all correlate. If they do not correlate, an error message is printed and the program terminates.

Prior to using the program, a vector called "Y" must be set in the APL work space. The vector consists of the output words in a sequence according to address. Thus, word number one must be entered first, followed by a blank space and then word number two, etc.

The next step is to define the physical mask dimensions to the program. This is done by entering the elements of two vectors "K" and "GR" into the work space (Fig. 2).

Program execution starts by entering PERS H V. "H" is the horizontal dimension of the array, and "V" is the vertical dimension.

Note that the product of these two numbers must equal the number...