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Product data sheet

Rev. 03 — 12 January 2005

7 of 21

Philips Semiconductors

74LVT16646A

3.3 V 16-bit bus transceiver; 3-state

7.

Functional description

7.1 Function table

[1]

H = HIGH voltage level;

L = LOW voltage level;

X = don’t care;

↑ = LOW-to-HIGH clock transition.

[2]

The data output function may be enabled or disabled by various signals at the nOE input. Data input functions are always enabled, i.e.

data at the bus pins will be stored on every LOW-to-HIGH transition of the clock.

50

positive supply voltage

1B1

51

data input or output 1; B side

1B0

52

data input or output 0; B side

GND

53

ground (0V)

1SBA

54

select inputs 0 to 7; B to A side

1CPBA

55

clock inputs 0 to 7; B to A side

1OE

56

output enable inputs 0 to 7

Table 3:

Symbol

Pin

Description

Table 4:

Function table [1]

Operating mode

Inputs

Data I/O

reference

nOE

nDIR

nCPAB

nCPBA

nSAB

nSBA

nAx

nBx

Store A (B unspecified)

X

X

↑

X

X

X

input

unspecified

output [2]

Figure 5c

Store B (A unspecified)

X

X

X

↑

X

X

unspecified

output [2]

input

Figure 5c

Store A and B data

H

X

↑↑

X

X

input

input

Figure 5c

Isolation, hold storage

H

X

H or L

H or L

X

X

input

input

-

Real time B data to A bus

L

L

X

X

X

L

output

input

Figure 5a

Stored B data to A bus

L

L

X

H or L

X

H

output

input

Figure 5d

Real time A data to B bus

L

H

X

X

L

X

input

output

Figure 5b

Stored A data to B bus

L

H

H or L

X

H

X

input

output

Figure 5d