SILICON GATE MOS 8708/8704

PROGRAMMING OPERATION

Description

Initially, and after each erasure, all bits of the 8708/8704 are in the "1" state (Output High). Information is introduced by select- ively programming "0" into the desired bit locations.

The circuit is set up for programming operation by raising the CS/WE input (Pin 20) to +12V. The word address is selected in the same manner as in the read mode. Data to be programmed are presented, 8-bits in parallel, to the data output lines (01-08).Logic levels for address and data lines and the supply voltages are the same as for the read mode. After address and data set up one program pulse (Vp) per address is applied to the program input (Pin 18). One pass through all addresses to be programmed is defined as a program loop. The number of loops (N) required is a function of the program pulse width (tpw) according to N x tpw ~ 100 ms.

For program verification, program loops and read loops may be alternated as shown in waveform B.

Program Characteristics

TA = 25°C, Vcc = +5V ±5%, Voo = +12V ±5%, Vss = -5V ±5%, Vss = OV, CS/WE = +12V, Unless Otherwise Noted.

Symbol

Parameter

Min.

Typ.

Max.

Units

tAS

Address Setup Time

10

 

 

llS

tcss

CS/WE Setup Time

10

 

 

llS

tos

Data Setup Time

10

 

 

llS

tAH

Address Hold Time

1

 

 

llS

tCH

CS/WE Hold Time

.5

 

 

lls

tOH

Data Hold Time

1

 

 

lls

tOF

Chip Deselect to Output Float Delay

0

 

120

ns

tOPR

Program To Read Delay

 

 

10

llS

tpw

Program Pulse Width

.1

 

1.0

ms

tpR

Program Pulse Rise Time

.5

 

2.0

llS

tpF

Program Pulse Fall Time

.5

 

2.0

llS

Ip

Programming Current

 

10

20

rnA

Vp

Program Pulse Amplitude

25

 

27

V

NOTE: Intels standard product warranty applies only to devices programmed to specifications described herein.

Erasing Procedure

The 8708/8704 may be erased by exposu re to high intensity short-wave ultraviolet Iight at a wavelength of 2537 A. The recom- mended integrated dose. (Le., UV intensity x exposure time) is 10W-sec/cm2 .Examples of ultraviolet sources which can erase the 8708/8704 in 20 to 30 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 8708/8704 to be erased should be placed about one inch away from the lamp tubes.

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Intel 8080 manual Parameter Min, TpF Program Pulse Fall Time, Programming Current RnA Program Pulse Amplitude
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8080 specifications

The Intel 8085 and 8080 microprocessors were groundbreaking innovations in the world of computing, paving the way for future microprocessor development and personal computing.

The Intel 8080, introduced in 1974, was an 8-bit microprocessor that played a fundamental role in the early days of personal computing. With a 16-bit address bus, it had the capability to address 64 KB of memory. Running at clock speeds of 2 MHz, the 8080 was notable for its instruction set, which included 78 instructions and 246 opcodes. It supported a range of addressing modes including direct, indirect, and register addressing. The 8080 was compatible with a variety of peripherals and played a crucial role in the development of many early computers.

The microprocessor's architecture was based on a simple and efficient design, making it accessible for hobbyists and engineers alike. It included an 8-bit accumulator, which allowed for data manipulation and storage during processing. Additionally, the 8080 featured registers like the program counter and stack pointer, which facilitated program flow control and data management. Its ability to handle interrupts also made it suitable for multitasking applications.

The Intel 8085, introduced in 1976, was an enhancement of the 8080 microprocessor. It maintained a similar architecture but included several key improvements. Notably, the 8085 had a built-in clock oscillator, simplifying system design by eliminating the need for external clock circuitry. It also featured a 5-bit control signal for status line management, which allowed for more flexible interfacing with peripheral devices. The 8085 was capable of running at speeds of up to 3 MHz and had an extended instruction set with 74 instructions.

One of the standout features of the 8085 was its support for 5 extra instructions for stack manipulation and I/O operations, which optimized the programming process. Additionally, it supported serial communication, making it suitable for interfacing with external devices. Its 16-bit address bus retained the 64 KB memory addressing capability of its predecessor.

Both the 8080 and 8085 microprocessors laid the groundwork for more advanced microprocessors in the years that followed. They demonstrated the potential of integrated circuits in computing and influenced the design and architecture of subsequent Intel microprocessors. Their legacy endures in the way they revolutionized computing, making technology accessible to a broader audience, and their influence is still felt in the design and architecture of modern microprocessors today.
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