Datasheet

SN54LVTH18646A, SN54LVTH182646A, SN74LVTH18646A, SN74LVTH182646A
3.3-V ABT SCAN TEST DEVICES
WITH 18-BIT TRANSCEIVERS AND REGISTERS
SCBS311D – MARCH 1994 – REVISED JUNE 1997
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
18 19
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
20
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
21 22 23 24
63 62 61 60 5964 58 56 55 5457
25 26 27 28 29
53 52
17
51 50 49
30 31 32
1OE GND 1CLKAB TDO 1A2 1A1 1SAB V 1SBA 1DIR 1B1 1B2 TMS 1CLKBA GND 1B3
2A9
GND
2SAB
2CLKAB
2A7 2A8
2OE
TDI
2CLKBA
2SBA
2DIR
2B9
V
TCK
GND
2B8
1A3
1A4
1A5
GND
1A6
1A7
1A8
1A9
V
CC
2A1
2A2
2A3
GND
2A4
2A5
2A6
1B4
1B5
1B6
GND
1B7
1B8
1B9
V
CC
2B1
2B2
2B3
2B4
GND
2B5
2B6
2B7
CC
CC
SN74LVTH18646A, SN74LVTH182646A . . . PM PACKAGE
(TOP VIEW)
FUNCTION TABLE
(normal mode, each 9-bit section)
INPUTS
DATA I/O
OPERATION OR FUNCTION
OE DIR CLKAB CLKBA SAB SBA A1–A9 B1–B9
OPERATION
OR
FUNCTION
X X ↑ X X X Input Unspecified
†
Store A, B unspecified
†
X XX ↑ X X Unspecified
†
Input Store B, A unspecified
†
H X ↑ ↑ X X Input Input Store A and B data
H X L L X X Input disabled Input disabled Isolation, hold storage
L L X X X L Output Input Real-time B data to A bus
L L X X X H Output Input disabled Stored B data to A bus
L H X X L X Input Output Real-time A data to B bus
L H X X H X Input disabled Output Stored A data to B bus
†
The data-output functions can be enabled or disabled by various signals at OE and DIR. Data-input functions are always enabled; i.e., data at
the bus terminals is stored on every low-to-high transition of the clock inputs.