NTE NTE6821 Datasheet

NTE6821

Integrated Circuit

Peripheral Interface Adapter (PIA),

NMOS, 1MHz

Description:

The NTE6821 is a peripheral interface adapter (PIA) in a 40–Lead DIP type package capable of inter­facing the Microprocessing Unit (MPU) to peripherals through two 8–Bit bidirectional peripheral data
buses and four control lines. No external logic is required for interfacing to most peripheral devices.

The functional configuration of the PIA is programmed by the MPU during system initialization. Each
of the peripheral data lines can be programmed to act as an input or output, and each of the four con­trol/interrupt lines may be programmed for one of several control modes. This allows a high degree
of flexibility in the over–all operation of the interface.

Features:

D 8–Bit Bidirectional Data Bus for Communication with the MPU
D Two Bidirectional 8–Bit Buses for Interface to Peripherals
D Two Programmed Control Registers
D Two Programmed Data Direction Registers
D Four Individually–Controlled Interrupt Input Lines; Two Usable as Peripheral Control Outputs
D Handshake Control Logic for Input and Output Peripheral Operation
D High–Impedance 3–State and Direct Transistor Drive Peripheral Lines
D Program Controlled Interrupt and Interrupt Disable Capability
D CMOS Drive Capability on Side A Peripheral Lines
D Two TTL Drive Capability on All A and B Side Buffers
D TTL Compatible
D Static Operation

Absolute Maximum Ratings: (Note 1)
Supply Voltage, V

Input Voltage, V
Operating Temperature Range, T
Storage Temperature Range, T
Thermal Resistance, Junction to Ambient, R

Note 1. This device contains circuitry to protect the inputs against damage due to high static voltages

or electric fields; however, it is advised that normal precautions be taken to avoid application
of any voltage higher than maximum rated voltages to this high impedance.

CC

in

A

stg

Θ

JA

–0.3 to +7V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

–0.3 to +7V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0° to +70°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

–55° to +150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

82.5°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Electrical Characteristics: (VCC = 5V ±5%, VSS = 0, TA = 0° to +70⁄C unless otherwise specified)

Parameter Symbol Test Conditions Min Typ Max Unit

Bus Control Inputs (R/W, Enable, Reset, RS0, RS1, CS0, CS1, CS2)

Input High Voltage V
Input Low Voltage V
Input Leakage Current I
Capacitance C

IH

IL

Vin = 0 to 5.25V – 1.0 2.5 µA

in

Vin = 0, TA = +25°C, f = 1MHz – – 7.5 pF

in

Interrupt Outputs (IRQA, IRQB)
Output Low Voltage V
Output Leakage Current (Off State) I
Capacitance C

LOH

I

OL

= 3.2mA – – VSS +0.4 V

Load

VOH = 2.4V – 1.0 10 µA
Vin = 0, TA = +25°C, f = 1MHz – – 5.0 pF

out

Data Bus (D0 – D7)
Input High Voltage V
Input Low Voltage V
Three–State (Off State) Input Current I
Output High Voltage V
Output Low Voltage V
Capacitance C

IH

TSI

OH
OL

IL

Vin = 0.4 to 2.4V – 2.0 10 µA
I

= –205µA VSS +2.4 – – V

Load

I

= 1.6mA – – VSS +0.4 V

Load

Vin = 0, TA = +25°C, f = 1MHz – – 12.5 pF

in

Peripheral Bus (PA0 – PA7, PB0 – PB7, CA1, CA2, CB1, CB2)
Input Leakage Current

R/W, Reset, RS0, RS1, CS0,

I

in

Vin = 0 to 5.25V – 1.0 2.5 µA

CS1, CS2, CA1, CB1, Enable

VSS +2.0 – V

CC

VSS –0.3 – VSS +0.8 V

VSS +2.0 – V

CC

VSS –0.3 – VSS +0.8 V

V

V

Three–State (Off State) Input Current

PB0 – PB7, CB2

Input High Current

PA0 – PA7, CA2

Darlington Drive Current

PB0 – PB7, CB2

Input Low Current

PA0 – PA7, CA2

Output High Voltage

PA0 – PA7, PB0 – PB7, CA2, CB2

PA0 – PA7, CA2 I
Output Low Voltage V
Capacitance C

V

I

I

TSI

I

IH

OH

I

IL

OH

OL

Vin = 0.4 to 2.4V – 2.0 10 µA

VIH = 2.4V –200 –400 – µA

VO = 1.5V –1.0 – –10 mA

VIL = 0.4V – –1.3 –2.4 mA

I

= –200µA VSS +2.4 – – V

Load

= 10µA VCC –1.0 – – V

Load

I

= 3.2mA – – VSS +0.4 V

Load

Vin = 0, TA = +25°C, f = 1MHz – – 10 pF

in

Power Requirements

Power Dissipation P

D

– – 550 mW

Bus Timing Characteristics: (VCC = 5V ±5%, VSS = 0, TA = 0° to +70°C unless otherwise specified)

Parameter Symbol Test Conditions Min Typ Max Unit

Enable Cycle Time t

cycE

Enable Pulse Width, High PW
Enable Pulse Width, Low PW
Enable Pulse Rise and Fall Times tEr, t

EH

EL

Ef

1000 – – ns

450 – – ns
430 – – ns

– – 25 ns