1
PS8135B
11/06/00
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PI74ALVCH16652
16-Bit Bus Transceiver and Register
with 3-State Outputs
ProductDescription
Pericom Semiconductors PI74ALVCH series of logic circuits are
producedintheCompanysadvanced0.5micronCMOStechnology,
achieving industry leading speed.
The PI74ALVCH16652 is a 16-bit bus transceiver and register
designed for low 2.3V to 3.6V Vcc operation. It consists of D-type
flip-flopsandcontrolcircuitryarrangedformultiplexedtransmission
of data directly from the data bus or from the internal storage
registers.Thedevicecanbeusedastwo8-bittransceiversorone16-
bit transceiver.
Complementary Output Enable (OEAB and OEBA) inputs are
provided to control the transceiver functions. Select Control (SAB
and SBA) inputs are provided to select whether real-time or stored
dataistransferred.Alowinputlevelselectsreal-timedata,andahigh
input level selects stored data. Circuitry used for Select Control
eliminates the typical decoding glitch that occurs in a multiplexer
during the transition between stored and real-time data.
Data on the A or B bus, or both, can be stored in the internal D flip-
flopsbylow-to-hightransitionsattheappropriateclock(CLKABor
CLKBA) inputs regardless of the levels on the Select Control or
Output Enable inputs. When SAB and SBA are in the real-time
transfer mode, it also is possible to store data without using the
internal D-type flip-lops by simultaneously enabling OEAB and
OEBA. In this configuration, each output reinforces its input. Thus,
whenallotherdatasourcestothetwosetsofbuslinesareinthehigh-
impedance state, each set of bus lines remains at its last level
configuration.
Active bus-hold circuitry is provided to hold unused or floating data
inputs at a valid logic level.
Toensurethehigh-impedancestateduringpoweruporpowerdown,
OEBA should be tied to Vcc through a pull-up resistor and OEAB
should be tied to GND through a pull-down resistor; the minimum
value of the resistor is determined by the current-sinking current
sourcing capability of the driver.
Product Features
PI74ALVCH16652 is designed for low voltage operation
VCC=2.3Vto3.6V
Hysteresis on all inputs
Typical VOLP (Output Ground Bounce)
< 0.8VatVCC = 3.3V,TA =25°C
Typical VOHV (Output VOH Undershoot)
< 2.0V atVCC = 3.3V,TA =25°C
Bus Hold retains last active bus state during 3-State,
eliminating the need for external pullup resistors
Industrial operation at 40°C to +85°C
Packages available:
56-pin 240 mil wide plastic TSSOP (A)
56-pin 300 mil wide plastic SSOP (V)
ProductPinConfiguration
1
OEAB
1
CLKAB
2
1
SAB
3
GND
4
1
A1
5
1
A2
6
VCC
7
1
A3
8
1
A4
9
1
A5
10
GND
11
1
A6
12
1
A7
13
1
A8
14
2
A1
15
2
A2
16
2
A3
17
GND
18
2
A4
19
2
A5
20
2
A6
21
VCC
22
2
A7
23
2
A8
24
1
OEBA
56
1
CLKBA
55
1
SBA
54
GND
53
1
B1
52
1
B2
51
VCC
50
1
B3
49
1
B4
48
1
B5
47
GND
46
1
B6
45
1
B7
44
1
B8
43
2
B1
42
2
B2
41
2
B3
40
GND
39
2
B4
38
2
B5
37
2
B6
36
VCC
35
2
B7
34
2
B8
33
GND
25
2
SAB
26
2
CLKAB
27
2
OEAB
28
GND
32
2
SBA
31
2
CLKBA
30
2
OEBA
29
56-Pin
A,V