Characteristics TA = oc to 70C Vee = +5V ±5% vss = OV

SILICON GATE MOS 8255

D.C. CHARACTERISTICS TA = o°c to 70°C; Vee = +5V ±5%; vss = OV
Symbol	Parameter	Min.	Typ. Max.	Unit	Test Conditions
Vil	Input Low Voltage		.8	V
VIH	Input High Voltage	2.0		V
Val	Output Low Voltage		.4	V	IOl = 1.6mA
VOH	Output High Voltage	2.4		V	IOH = -50JlA (-1 OOJlA for D.B. Port)
IOH[1]	Darlington Drive Current		2.0	rnA	VOH=1.5V, REXT=390n
Ice	Power Supply Current		40	rnA
NOTE:

1. Available on 8 pins only.

A.C. CHARACTERISTICS TA = o°c to 70°C; Vee = +5V ±6%; Vss = OV

Symbol	Parameter
twP	Pulse Width of WR
tow	Time D.B. Stable Before WR
two	Time D.B. Stable After WR
tAW	Time Address Stable Before WR
tWA	Time Address Stable After WR
tew	Time CS Stable Before WR
twe	Time CS Stable After WR
tWB	Delay From WR To Output
tRP	Pulse Width of RD
tlR	-
tlR	RD Set-Up Time
tHR	Input Hold Time
tRO	Delay From RD = 0 To System Bus
too	Delay From RD = 1 To System Bus
tAR	Time Address Stable Before RD
teR	Time CS Stable Before RD
tAK	Width Of ACK Pulse
tST	Width Of STB Pulse
tps	Set-Up Time For Peripheral
tpH	Hold Time For Peripheral
tRA	Hold Time for A1, Ao After RD = 1
'IRe	Hold Time For CS After RD = 1
'IRe
tAD	Time From ACK = 0 To Output(Mode 2)
tKO	Time From ACK = 1 To Output Floating
two	Time From WR = 1 To OBF = 0
tAO	Time From ACK = 0 To OBF = 1
	-
tSI	Time From STB = 0 To IBF
tRI	Time From RD = 1 To IBF = 0

Min. Typ. Max.	Unit	Test Condition
430	ns
10	ns
65	ns
20	ns
35	ns
20	ns
35	ns
500	ns
430	ns
50	ns
50	ns
350	ns
150	ns
50	ns
50	ns
500	ns
350	ns
150	ns
150	ns
379	ns
5	ns
500	ns
300	ns
300	ns
500	ns
600	ns
300	ns

5-130

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.

Intel 8080 manual Characteristics TA = oc to 70C Vee = +5V ±5% vss = OV, Vil Input Low Voltage

Models: 8080

D.C. CHARACTERISTICS TA = o°c to 70°C; Vee = +5V ±5%; vss = OV

Unit

Vil

Input Low Voltage

Input High Voltage

Val

Output Low Voltage

IOl = 1.6mA

Time From STB = 0 To IBF

tRI

Time From RD = 1 To IBF = 0

Unit

430

500

350

500

350

150

379

300

600

8080 specifications