Intel 8080 manual Programming Instructions for the 8702A, Operation of the 8702A in Program Mode

SILICON GATE MOS 8702A

PROGRAMMING INSTRUCTIONS FOR THE 8702A

I.Operation of the 8702A in Program Mode

Initially, all 2048 bits of the ROM are in the "0" state (output low). Information is introduced by se\ectively program- ming "1 "s (output high) in the proper bit locations.

Word address selection is done by the same decoding circuitry used in the READ mode (see table on page 6 for logic levels). All 8 address bits must be in the binary complement state when pulsed VDD and VGG move to their nega- tive levels. The addresses must be held in their binary complement state for a minimum of 25 p'secafter VDD and VGG have moved to their negative levels. The addresses must then make the transition to their true state a minimum of 10 p'secbefore the program pulse

is applied. The addresses should be programmed in the sequenc~ 0 through 255 for a minimum of 32 times. The eight output terminals are used as data inputs to determine the information pattern in the eight bits of each word. A low data input level (- 48V) will pro- gram a "1" and a high data input level (ground) will leave a "0" (see table on page 6). All eight bits of one word are programmed simultaneously by setting the desired bit information patterns on the data input terminals.

During the programming, VGG , VDD and the Program Pulse are pulsed signals.

II.Programming of the 8702A Using Intel ® Microcomputers

Intel provides low cost program devel- opment systems which may be used to program its electrically programmable ROMs. Note that the programming specifications that apply to the 8702A are identical to those for Intel's1702A.

A.Intellec®

The Intellec series of program de- velopment systems, the Intellec 8/Mod 8 and Intellec 8/Mod 80, are used as program development tools for the 8008 and 8080 microproces- sors respectively. As such, they are equipped with a PROM programmer card and may be used to program Intel'selectrically programmable and ultraviolet erasable ROMs.

An ASR-33 teletype terminal is used as the input device. Through use of the InteHec software system monitor, programs to be loaded into PROM may be typed in directly or loaded through the paper tape reader. The system monitor allows the program to be reviewed or altered at will prior to actually programming the PROM. For more complete informa- tion on these program development systems, refer to the Intel Micro- computer Catalog or the Intellec Specifications.

B.Users of the SIM8 microcomputer programming systems may also program the 8702A using the MP7-03 programmer card and the appropriate control ROMs:

SIM8 system-Control ROMs A0860, A0861 and A0863.

III. 8702A Erasing Procedure

The 8702A may be erased by expo- sure to high intensity short-wave ultra- violet light at a wavelength of 2537A. The recommended integrated dose (Le., UV intensity x exposure time) is

6W-sec/cm2•Examples of ultraviolet sources which can erase the 8702A in 10 to 20 minutes are the Model UVS-54 and Model S-52 short-wave ultraviolet lamps manufactured by Ultra-Violet Products, Inc. (5114 Walnut Grove Avenue, San Gabriel, California). The lamps should be used without short-wave filters, and the 8702A to be erased should be placed about one inch away from the lamp tubes.

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