intJ8085A18085A·2

A.C. CHARACTERISTICS (Continued)

Symbol

Parameter

8085A(2)

8085A·2(2)

Units

 

 

Min.

Max.

Min.

Max.

 

tRAE

Trailing Edge of READ to Re·Enabling

150

 

90

 

ns

 

of Address

 

 

 

 

 

tRD

READ (or INTA) to Valid Data

 

300

 

150

ns

tRV

Control Trailing Edge to leading Edge

400

 

220

 

ns

 

of Next Control

 

 

 

 

 

tRDH

Data Hold Time After READ INTA(7)

0

 

0

 

ns

tRYH

READY Hold Time

0

 

0

 

ns

tRYS

READY Setup Time to leading Edge

110

 

100

 

ns

 

of ClK

 

 

 

 

 

tWD

Data Valid After Trailing Edge of WRITE

100

 

60

 

ns

tWDl

lEADING Edge of WRITE to Data Valid

 

40

 

20

ns

NOTES:

1.Aa-A15 address Specs apply to 101M, So'and S1 except Aa-A15 are undefined during T4-T6 of OF cycle whereas 101M, So'andS1 are stable.

2.Test conditions: tCYC =320ns (8085A)/200 ns (8085A-2); CL =150 pF.

3.For all output timing where CL = 150pF use the following correction factors: 25pF .. CL < 150pF: -0.10ns/pF

150pF < CL" 300pF: +0.30ns/pF

4.Output timings are measured with purely capacitive load.

5.All timings are measured at output votage VL = 0.8V, VH = 2.0V, and 1.5V with 20 ns rise and fall time on inputs.

6.To calculate timing specifications at other values of tCYC use Table 7.

7.Data hold time is guaranteed under all loading conditions.

A.C. TESTING INPUT, OUTPUT WAVEFORM

INPUT/OUTPUT

"=X2.00.8 '?TEST POINTS <0.82.0 )C 0.45

A.C. TESTING: INPUTS ARE DRIVEN AT 2.4V FOR A LOGIC "1" AND 0.45V FOR A LOGIC "0." TIMING MEASUREMENTS ARE MADE AT 2.0V FOR A LOGIC "1" AND O.SV FOR A LOGIC "0."

A.C. TESTING LOAD CIRCUIT

DEVICE

UNDER

TEST 1"'""'"

CL = 150 pF

CL INCLUDES JIG CAPACITANCE

6-29

AFN-01242C

Page 138
Image 138
Intel MCS-80/85 Symbol Parameter 8085A2 8085A·22 Units Min Max, Trailing Edge of Read to Re·Enabling, Ready Hold Time

MCS-80/85 specifications

The Intel MCS-80/85 family, introduced in the late 1970s, is a seminal collection of microprocessors that played a pivotal role in the early days of computing. The MCS-80 series, initially targeting embedded systems and control applications, gained remarkable attention due to its innovative architecture and flexible programming capabilities.

The MCS-80 family is anchored by the 8080 microprocessor, which was one of the first fully integrated 8-bit microprocessors. Released in 1974, the 8080 operated at clock speeds ranging from 2 MHz to 3 MHz and featured a 16-bit address bus capable of addressing up to 64KB of memory. The processor’s instruction set included around 78 instructions, providing extensive capabilities for data manipulation, logic operations, and branching.

Complementing the 8080 was a suite of support chips, forming the MCS-80 platform. The most notable among them was the 8155, which integrated a static RAM, I/O ports, and a timer, tailored for ease of designing systems around the 8080. Other support chips included the 8085, which provided improvements with an integrated clock generator, making it compatible with more modern designs and applications.

The MCS-85 series, on the other hand, revolves around the 8085 microprocessor, which provided a more advanced architecture. The 8085 operated at clock speeds of up to 6 MHz and came with a 16-bit address bus, similar to its predecessor. However, it introduced more sophisticated features, including an enhanced instruction set and support for interrupt-driven programming. These enhancements made the 8085 especially appealing to developers working in real-time processing environments.

The MCS-80/85 family utilized NMOS technology, known for its lower power consumption and higher performance compared to previous technologies like TTL. The family’s architecture allowed for easy interfacing with a variety of peripherals, making it a favorite for educational institutions and hobbyists embarking on computer engineering projects.

With its robustness, versatility, and affordability, the Intel MCS-80/85 microprocessors laid the groundwork for many subsequent microcomputer systems and applications. The legacy of this powerful family continues to influence modern microprocessor design, emphasizing the importance of reliable architecture in a rapidly evolving technology landscape.