74ABT16652 Fairchild Semiconductor, 74ABT16652 Datasheet - Page 2

• Manufacturer Part Number: 74ABT16652
• Description: 16-Bit Transceivers and Registers with 3-STATE Outputs
• Manufacturer: Fairchild Semiconductor

www.fairchildsemi.com
Functional Description
In the transceiver mode, data present at the HIGH imped-
ance port may be stored in either the A or B register or
both.
The select (SAB
real-time.
The examples in Figure 1 demonstrate the four fundamen-
tal bus-management functions that can be performed with
the ABT16652.
OEAB
OEAB
H
1
L
1
n
Transfer Bus B to Bus A
Transfer Bus A to Bus B
OEBA
OEBA
, SBA
H
L
1
1
Note A: Real-Time
Note B: Real-Time
n
) controls can multiplex stored and
CPAB
CPAB
X
X
1
1
CPBA
CPBA
X
X
1
1
SAB
SAB
X
L
1
1
SBA
SBA
X
L
1
1
FIGURE 1.
2
Data on the A or B data bus, or both can be stored in the
internal D flip-flop by LOW to HIGH transitions at the
appropriate Clock Inputs (CPAB
the Select or Output Enable Inputs. When SAB and SBA
are in the real time transfer mode, it is also possible to
store data without using the internal D flip-flops by simulta-
neously enabling OEAB
each Output reinforces its Input. Thus when all other data
sources to the two sets of bus lines are in a HIGH imped-
ance state, each set of bus lines will remain at its last state.
OEAB
OEAB
H
1
X
1
L
L
OEBA
Note D: Transfer Storage
OEBA
1
L
H
H
X
1
Note C: Storage
Data to A or B
CPAB
n
H or L H or L
CPAB
and OEBA

 
X
1
1
CPBA
CPBA
n

, CPBA
X
1
1
n
. In this configuration
SAB
SAB
X
X
X
1
n
H
1
) regardless of
SBA
SBA
X
X
X
1
H
1