CPU Functional Block Diagram, SA Pin | Intel MCS-80/85 manual

808SA/808SA-2

SINGLE CHIP 8-BIT N-CHANNEL MICROPROCESSORS

•Single +5V Power Supply

..• 100% Software Compatible with SOSOA 1.3 p,s Instruction Cycle (SOS5A);

O.S p,s (SOS5A-2)

• On-Chip Clock Generator (with External Crystal, LC or RC Network)

• On-Chip System Controller; Advanced Cycle Status Information Available for Large System Control

•Four Vectored Interrupt Inputs (One is Non-Maskable) Plus an SOSOA- Compatible Interrupt

•Serial In/Serial Out Port

•Decimal, Binary and Double Precision Arithmetic

•Direct Addressing Capability to 64k Bytes of Memory

The Intel@ 8085A is a complete 8 bit parallel Central Processing Unit (CPU). Its instruction set is 100% software compatible with the 8080A microprocessor, and it is designed to improve the present 80BOA'sperformance by higher system speed. Its high level of system integration allows a minimum system of three IC's[8085A (CPU), 8156 (RAM/IO) and 8355/8755A (ROM/PROM/IO)] while maintaining total system expandability. The 8085A-2 is a faster version of the 8085A.

The 8085A incorporates all of the features that the 8224 (clock generator) ,and 8228 (system controller) provided for the 8080A, thereby offering a high level of system integration.

The 8085A uses a multiplexed data bus. The address is split between the 8 bit address bus and the 8 bit data bus. The on-chip address latches of 8155/8156/8355/8755A memory products allow a direct interface with the 8085A.

IN'TARST6.5

1~::~)!:~}~~~I!~ER

INCREMENTER/DECREMENTER

ADDRESS LATCH 116)

Xl	Vee
X2	HOLD
,RESET OUT	HlDA
SOD	elK (OUT)
SID	RESET IN
TRAP	READY
RST 7.5	101M
RST 6,5	Sl
RST 5.5	AD
INTR	WR
INTA	ALE
ADO	So
ADI	A15
AD2	A14
AD3	A13
AD4	A12
AD5	All
AD6	AlO
AD7	Ag

VSS ...___r AS

A1S-AS	AD7-ADO
ADDRESS BUS	ADDRESS/DATA BUS
Figure 1. 8085A CPU Functional Block Diagram	Figure 2. 808SA Pin
Figure 1. 8085A CPU Functional Block Diagram	Configuration

6-26	AFN-01242C

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.

Intel MCS-80/85 manual CPU Functional Block Diagram, SA Pin

Models: MCS-80/85

SINGLE CHIP 8-BIT N-CHANNEL MICROPROCESSORS

1~::~)!:~}~~~I!~ER

Figure 1. 8085A CPU Functional Block Diagram

Figure 2. 808SA Pin

MCS-80/85 specifications