AT16646
Fast Logic

16-Bit
Tri-State

Register
AT16646F
AT16646G
Features
•
Fastest Propagation Speeds in the Industry T
PD (F grade)
= 2.5 ns, T
PD (G grade)
= 2.0 ns
•
Maximum derating for capacitive loads 1.5ns/100 pF (F grade) and 1.1ns/100 pF
(G grade)
•
Very low ground bounce < 0.6 V @ V
CC
=5.00 V, T
a
=25°C
•
Typical output skew ≤0.25ns
•
Bus Hold circuitry to retain last active state during Tri-State
•
Available in SSOP and TSSOP packages
Description
Atmel’s AT16646 devices are 16-bit high speed, low power Tri-statable D type
registers, ideal for use in systems requiring both transparent and registered mode
functions. They are organized as two separate 8-bit bus transceivers. Data flow is
bi-directional, and can be controlled for multiplexed transmission between A bus and
B bus either directly or from the D registers by use of the direction control pin (xDir),
output enable (xOE), and select lines (xSAB and xSBA). Storage of data on the A bus
and B bus is controlled by the output pins. They have very low ground bounce and
excellent input noise rejection, giving the user stable signals in a high speed
environment. The Bus Hold feature eliminates the need for pull-up or pull-down
resistors and retains the last active state during a Tri-State event.
Functional Block Diagram
Pin Names Descriptions
xDir, xOE Output Enable Inputs
xCLKAB,xCLKBA Clock Pulse Inputs
xSAB, xSBA Output Data Source Select Inputs
xAχ Data Register A Inputs
Data Register B Outputs
xBχ Data Register B Inputs
Data Register A Outputs
Pin Configurations
1
3
5
7
9
11
13
15
17
19
21
23
25
27
55
53
51
49
47
45
43
41
39
37
35
33
31
29
56
54
52
50
48
46
44
42
40
38
36
34
32
30
2
4
6
8
10
12
14
16
18
20
22
24
26
28
1CLKAB
GND
1A2
1A3
1A5
1A6
1A8
2A2
GND
2A5
VCC
2A8
2SAB
2DIR
1
1SBA
1B1
VCC
1B4
GND
1B7
2B1
2B3
2B4
2B6
2B7
GND
2CLKBA
OE
1CLKBA
GND
1B2
1B3
1B5
1B6
1B8
2B2
GND
2B5
VCC
2B8
2SBA
2OE
1DIR
1SAB
1A1
VCC
1A4
GND
1A7
2A1
2A3
2A4
2A6
2A7
GND
2CLKAB
SSOP/TSSOP
Top View
0757B
AT16646
5-21