CY29FCT818T_15 Datasheet, PDF (1/14 Pages) Texas Instruments – DIAGNOSTIC SCAN REGISTER WITH 3-STATE OUTPUTS

D Function, Pinout, and Drive Compatible
With FCT, F Logic, and AM29818
D Reduced V_OH (Typically = 3.3 V) Version of
Equivalent FCT Functions
D Edge-Rate Control Circuitry for
Significantly Improved Noise
Characteristics
D I_off Supports Partial-Power-Down Mode
Operation
D Matched Rise and Fall Times
D Fully Compatible With TTL Input and
Output Logic Levels
D 8-Bit Pipeline and Shadow Register
D ESD Protection Exceeds JESD 22
– 2000-V Human-Body Model (A114-A)
– 200-V Machine Model (A115-A)
– 1000-V Charged-Device Model (C101)
D CY29FCT818CT
– 64-mA Output Sink Current
– 32-mA Output Source Current
D CY29FCT818ATDMB
– 20-mA Output Sink Current
– 3-mA Output Source Current
D 3-State Outputs
CY29FCT818T
DIAGNOSTIC SCAN REGISTER
WITH 3-STATE OUTPUTS
SCCS012B – MAY 1994 – REVISED NOVEMBER 2001
D, P, Q, OR SO PACKAGE
(TOP VIEW)
OE ₁
DCLK ₂
D_{0 3}
D₁ 4
D₂ 5
D₃ 6
D₄ 7
D₅ 8
D₆ 9
D₇ 10
SDI 11
GND 12
24 ^V_CC
23 ^MODE
22 ^Y₀
21 Y₁
20 Y₂
19 Y₃
18 Y₄
17 Y₅
16 Y₆
15 Y₇
14 SDO
13 PCLK
description
The CY29FCT818T contains a high-speed 8-bit general-purpose data pipeline register and a high-speed 8-bit
shadow register. The general-purpose register can be used in an 8-bit-wide data path for a normal system
application. The shadow register is designed for applications such as diagnostics in sequential circuits, where
it is desirable to load known data at a specific location in the circuit and to read the data at that location.
The shadow register can load data from the output of the device, and can be used as a right-shift register with
bit-serial input (SDI) and output (SDO), using DCLK. The data register input is multiplexed to enable loading
from the shadow register or from the data input pins, using PCLK. Data can be loaded simultaneously from the
shadow register to the pipeline register, and from the pipeline register to the shadow register, provided
setup-time and hold-time requirements are satisfied, with respect to the two independent clock inputs.
In a typical application, the general-purpose register in this device replaces an 8-bit data register in the normal
data path of a system. The shadow register is placed in an auxiliary bit-serial loop that is used for diagnostics.
During diagnostic operation, data is shifted serially into the shadow register, then transferred to the
general-purpose register to load a known value into the data path. To read the contents at that point in the data
path, the data is transferred from the data register into the shadow register, then shifted serially in the auxiliary
diagnostic loop to make it accessible to the diagnostics controller. This data then is compared with the expected
value to diagnose faulty operation of the sequential circuit.
This device is fully specified for partial-power-down applications using I_off. The I_off circuitry disables the outputs,
preventing damaging current backflow through the device when it is powered down.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
Copyright  2001, Texas Instruments Incorporated
On products compliant to MIL-PRF-38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
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