Philips hef4755v DATASHEETS

INTEGRATED CIRCUITS

DATA SH EET

For a complete data sheet, please also download:

•The IC04 LOCMOS HE4000B Logic
Family Specifications HEF, HEC

•The IC04 LOCMOS HE4000B Logic
Package Outlines/Information HEF, HEC

HEF4755V
LSI

Transceiver for serial data
communication

Product specification
File under Integrated Circuits, IC04

January 1995

Philips Semiconductors Product specification

Transceiver for serial data communication

DESCRIPTION

The HEF4755V transceiver is a circuit for serial data
communication. It provides maximum transmission
security and effectiveness. Therefore, in addition to the
normal precautions, it contains a programmable digital
bit-check, a programmable CRC (Cyclic Redundancy
Check; Hamming distance 4 or 6) and format protection.

The circuit has 8 possible operating modes:

• synchronous
– error checking only
– receiving
– transmitting
– receiving with data out and transmitting the same

message

• asynchronous
– error checking only
– receiving
– transmitting
– receiving with data out and transmitting of a

regenerated message.

SUPPLY VOLTAGE/CURRENT

V

DD

I

SS

FAMILY DATA, I

See Family Specification

HEF4755V

LSI

RATING RECOMMENDED OPERATING

−0,5 to +15 4,75 to 12,6 V
30 − mA

LIMITS category LSI

DD

FEATURES

• Transmission rate:

V

DD

10 V 3,2 Mbaud 125 kbaud

• Inputs: standard LOCMOS

• Outputs: TTL compatible (1 TTL load)

• Operating ambient temperature range: −40 to + 85 °C

• Transmit or receive a serial binary data stream

• Start bit generation and recognition

• Format protection and checking

• Redundancy byte generation and checking

• Digital bit check

• Error recognition and error distinguishing

• 8-bit parallel input/output transfer

SYNCHRONOUS ASYNCHRONOUS

5 V 0,8 Mbaud 31 kbaud
7 V 1,6 Mbaud 62 kbaud

Fig.1 Pinning diagram.

January 1995 2

Philips Semiconductors Product specification

Transceiver for serial data communication

HEF4755VP(N): 28-lead DIL; plastic

(SOT117-2)

HEF4755VD(F): 28-lead DIL; ceramic (cerdip)

(SOT135)

HEF4755VT(D): 28-lead SO; plastic

(SOT136-1)

( ): Package Designator North America

PINNING

1 TST Test pin; during normal use

connected to V
HIGH (VDD), internal check points

are connected to the data bus.
2 ML0 Input code for message length (see
3 ML1

4 DIO0

11 DIO7
12 RX Mode input: receive; see Table 2
13 TX Mode input: transmit; see Table 2
15 AS Mode input: asynchronous;

16 R Reset; a positive signal resets

17 START Input start in transmitting mode;

18 BUSY Output busy; active during

Table 1).

Bidirectional data bus.to to

see Table 2

all internal registers.

synchronization input (from MOS)

in synchronous receiving mode.

receiving or transmitting a message.

. When TST is

SS

HEF4755V

LSI

19 HD Hamming distance; determines the

length of the redundancy byte:
LOW = 7 bit (HD = 4)
HIGH = 15 bit (HD = 6)

20 MOS Output message synchronization

used in synchronous mode.
21 MO Message output.
22 MI Message input.
23 DP Output data pulse; take-over pulse

for data on the data bus.
24 ERR Output error; an active output

means that at least 1 transmission

error is recognized.
25 CP Clock input; in synchronous mode

equal to the transmission bit rate.
26 TT1 Programming of the permissible time
27 TT0

28 V

14 V

DD

SS

tolerance in bit distortion

(see Table 3).

Positive supply voltage; 4,5 V to

12,5 V (is the logic HIGH level).

Ground (is the logic LOW level).

January 1995 3

Philips Semiconductors Product specification

Transceiver for serial data communication

Table 1 Input code for message length

ML0 ML1 MESSAGE LENGTH

H H 6 data bytes

L H 4 data bytes

H L 2 data bytes

variable length

LL

Table 2 Input code for input mode

RX TX AS

L L L status register connected to the data bus for error recognition
H L L receiving in synchronous mode
L H L transmitting in synchronous mode
H H L receiving messages (without redundancy bit); data parallel out;

L L H only bit check in asynchronous mode; no data output on data bus
H L H receiving in asynchronous mode
L H H transmitting in asynchronous mode
H H H receiving and transmitting of a regenerated message in the

depends on
format byte

calculating of redundancy byte; transmitting data with redundancy
byte in synchronous mode

asynchronous mode

HEF4755V

LSI

Table 3 Permissible time tolerance in bit distortion

TT1 TT0 PERMITTED DISTORTION (dt/T)

L L 6/32 ≈ 19%
L H 8/32 = 25%
H L 10/32 ≈ 31%
H H 12/32 ≈ 37%

Notes

1. H = HIGH state (the most positive voltage)

2. L = LOW state (the least positive voltage)

January 1995 4