8355*/8355-2**

16,384·8IT ROM WITH 110

*Directly Compatible with 8085A CPU

**Directly Compatible with 8085A-2

2048 Words x 8 Bits

Single + 5V Power Supply

Internal Address Latch

2 General Purpose 8·Bit \/0 Ports

Each \/0 Port Line Individually Programmable as Input or Output

Multiplexed Address and Data Bus

40·Pin DIP

The Intel® 8355 is a ROM and I/O chip to be used in the MCS-85'·microcomputer system. The ROM portion is organized as 2048 words by 8 bits. It has a maximum access time of 400 ns to permit use with no wait states in the 8085A CPU.

The 1/0 portion consists of 2 general purpose 1/0 ports. Each 1/0 port has 8 port lines, and each 1/0 port line is indivduo ally programmable as input or output.

The 8355-2 has a 300ns access time for compatibility with the 8085A-2 microprocessor.

PIN CONFIGURATION

BLOCK DIAGRAM

 

Vee

 

 

 

 

 

PB,

elK

 

 

 

 

 

 

 

 

 

PB,

 

 

 

 

RESET

PB,

READY

 

 

 

N.C. (NOT CONNECTED) 5

PB,

 

 

 

 

 

 

 

 

PB,

ADo_7

 

~

 

 

PB,

 

 

 

 

PB,

A B- 10

 

PA -

RD

 

 

O 7

PB.

eE,

 

 

lOW

PA,

 

 

CE,

 

 

 

ROM

 

 

PA,

101M

G~

 

AD.

PAs

 

ALE

PB -

AD,

PA,

O 1

RD

 

 

 

 

AD,

PA,

lOW

 

RESET

 

AD,

PA,

iDA

 

 

 

 

 

 

 

 

AD,

PAD

 

 

 

 

AD,

 

 

 

 

 

AD,

 

 

 

Vee

(+5VI

 

 

 

 

 

VSS

 

 

 

Vss

fOV)

 

 

 

 

 

INT£l CORPORATION ASSlHS NO RESPONSIBIlITY FOR THE USE OF ANY CIRCUITRY OTHER THAN CIICUITRY EMBOOIEO IN AN IIITEl PROOOCT. NO OTItER CIRCIIIT PATENT LICENSES ARE IMPLIED. "INTEL CORPORATION. 1979

6-69

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Intel mcs-48 manual 16,384·8IT ROM with