SN54AS856, SN74AS856

8BIT UNIVERSAL TRANSCEIVER PORT CONTROLLERS

SDAS032A − DECEMBER 1983 − REVISED MARCH 1985

POST OFFICE BOX 655303

7

switching characteristics (see Note 1)

VCC = 4.5 V to 5.5 V,

CL = 50 pF,

FROM

TO

R1 = 500

Ω,

PARAMETER

FROM

(INPUT)

TO

(OUTPUT)

R2 = 500

UNIT

PARAMETER

(INPUT)

(OUTPUT)

TA = MIN to MAX

SN54AS856

SN74AS856

MIN

MAX

MIN

MAX

fmax

45

50

MHz

tPLH

Any B port

Any A port

2

8

2

7

ns

tPHL

Any B port

Any A port

2

10.5

2

9.5

ns

tPLH

↑MODE

Any A or B

2

8.5

2

7.5

ns

tPHL

↑MODE

port

5

20

5

19

ns

tPLH

↓MODE †

Any A or B

2

8.5

2

7.5

ns

tPHL

↓MODE †

port

2

9.5

2

8

ns

tPLH

CLK

Any A or B

3

12

3

9

ns

tPHL

CLK

port

3

12

3

11

ns

tPLH

CLK

Q8

2

9

2

7.5

ns

tPHL

CLK

Q8

2

10

2

9

ns

tPHZ

2

9

2

7

ns

tPLZ

OEA or OEB

Any A or B

2

12

2

9.5

ns

tPZH

OEA or OEB

Any A or B

port

2

8

2

7

ns

tPZL

port

2

11

2

10

ns

† The positive transition of the MODE control will cause low-level data at the A output bus or stored in Q to be invalid for 12 ns.

NOTE 1: Load circuit and voltage waveforms are shown in Section 1.