TL/F/10637
74AC899 #54ACT/74ACT899
9-Bit Latchable Transceiver with Parity Generator/Checker
August 1994
74AC899 #54ACT/74ACT899
9-Bit Latchable Transceiver
with Parity Generator/Checker
General Description
The ’AC/’ACT899 is a 9-bit to 9-bit parity transceiver with
transparent latches. The device can operate as a feed-
through transceiver or it can generate/check parity from the
8-bit data busses in either direction. The ’AC/’ACT899 fea-
tures independent latch enables for the A-to-B direction and
the B-to-A direction, a select pin for ODD/EVEN parity, and
separate error signal output pins for checking parity.
Features
YLatchable transceiver with output sink of 24 mA
YOption to select generate parity and check or ‘‘feed-
through’’ data/parity in directions A-to-B or B-to-A
YIndependent latch enable for A-to-B and B-to-A direc-
tions
YSelect pin for ODD/EVEN parity
YERRA and ERRB output pins for parity checking
YAbility to simultaneously generate and check parity
YMay be used in system applications in place of the ’280
YMay be used in system applications in place of the ’657
and ’373 (no need to change T/R to check parity)
Y4 kV minimum ESD immunity
Logic Symbol
TL/F/106371
Connection Diagram
Pin Assignment for PCC and LCC
TL/F/106372
TRI-STATEÉis a registered trademark of National Semiconductor Corporation.
FACTTM is a trademark of National Semiconductor Corporation.
C1995 National Semiconductor Corporation RRD-B30M75/Printed in U. S. A.
Pin Names Description
A0–A7A Bus Data Inputs/Data Outputs
B0–B7B Bus Data Inputs/Data Outputs
APAR, BPAR A and B Bus Parity Inputs
ODD/EVEN ODD/EVEN Parity Select, Active
LOW for EVEN Parity
GBA, GAB Output Enables for A or B Bus,
Active LOW
SEL Select Pin for Feed-Through or
Generate Mode, LOW for Generate
Mode
LEA, LEB Latch Enables for A and B Latches,
HIGH for Transparent Mode
ERRA, ERRB Error Signals for Checking
Generated Parity with Parity In,
LOW if Error Occurs
Functional Description
The ’AC/’ACT899 has three principal modes of operation
which are outlined below. These modes apply to both the A-
to-B and B-to-A directions.
Ð Bus A (B) communicates to Bus B (A), parity is generat-
ed and passed on to the B (A) Bus as BPAR (APAR). If
LEB (LEA) is HIGH and the Mode Select (SEL) is LOW,
the parity generated from B[0:7](A[0:7]) can be
checked and monitored by ERRB (ERRA).
Ð Bus A (B) communicates to Bus B (A) in a feed-through
mode if SEL is HIGH. Parity is still generated and
checked as ERRA and ERRB in the feed-through mode
(can be used as an interrupt to signal a data/parity bit
error to the CPU).
Ð Independent Latch Enables (LEA and LEB) allow other
permutations of generating/checking (see Function Ta-
ble below).
Function Table
Inputs Operation
GAB GBA SEL LEA LEB
H H X X X Busses A and B are TRI-STATEÉ.
H L L L H Generates parity from B[0:7]based on O/E (Note 1). Generated parity
x
APAR. Generated parity checked against BPAR and output as
ERRB.
H L L H H Generates parity from B[0:7]based on O/E. Generated parity
x
APAR. Generated parity checked against BPAR and output as ERRB.
Generated parity also fed back through the A latch for generate/check
as ERRA.
H L L X L Generates parity from B latch data based on O/E. Generated parity
x
APAR. Generated parity checked against latched BPAR and
output as ERRB.
H L H X H BPAR/B[0:7]
x
APAR/A0:7]Feed-through mode. Generated parity
checked against BPAR and output as ERRB.
H L H H H BPAR/B[0:7]
x
APAR/A[0:7]
Feed-through mode. Generated parity checked against BPAR and
output as ERRB. Generated parity also fed back through the A latch for
generate/check as ERRA.
L H L H L Generates parity for A[0:7]based on O/E. Generated parity
x
BPAR. Generated parity checked against APAR and output as ERRA.
L H L H H Generates parity from A[0:7]based on O/E. Generated parity
x
BPAR. Generated parity checked against APAR and output as ERRA.
Generated parity also fed back through the B latch for generate/check
as ERRB.
L H L L X Generates parity from A latch data based on O/E. Generated parity
x
BPAR. Generated parity checked against latched APAR and
output as ERRA.
L H H H L APAR/A[0:7]
x
BPAR/B[0:7]
Feed-through mode. Generated parity checked against APAR and
output as ERRA.
L H H H H APAR/A[0:7]
x
BPAR/B[0:7]
Feed-through mode. Generated parity checked against APAR and
output as ERRA. Generated parity also fed back through the B latch for
generate/check as ERRB.
HeHIGH Voltage Level
LeLOW Voltage Level
XeImmaterial
Note 1: O/E eODD/EVEN
2
Functional Block Diagram
TL/F/106373
AC Path
TL/F/106374
An, APAR
x
Bn, BPAR
(Bn, BPAR
x
An, APAR)
FIGURE 1
3
AC Path (Continued)
An
x
BPAR
(Bn
x
APAR) TL/F/106375
FIGURE 2
An
x
ERRA
(Bn
x
ERRB) TL/F/106376
FIGURE 3
O/E
x
ERRA
O/E
x
ERRB TL/F/106377
FIGURE 4
4
AC Path (Continued)
O/E
x
BPAR
(O/E
x
APAR) TL/F/106378
FIGURE 5
APAR
x
ERRA
(BPAR
x
ERRB) TL/F/106379
FIGURE 6
TL/F/1063710
ZH, HZ
FIGURE 7
5
AC Path (Continued)
TL/F/1063711
ZL, LZ
FIGURE 8
TL/F/1063712
SEL
x
BPAR
(SEL
x
APAR)
FIGURE 9
TL/F/1063713
LEA
x
BPAR, B[0:7]
(LEB
x
APAR, A[0:7])
FIGURE 10
6
AC Path (Continued)
TS(H), TH(H)
TL/F/1063714
LEA
x
APAR, A[0:7]
(LEB
x
BPAR, B[0:7])
FIGURE 11
TS(L), TH(L)
TL/F/1063715
LEA
x
APAR, A[0:7]
(LEB
x
BPAR, B[0:7])
FIGURE 12
TL/F/1063716
FIGURE 13
7
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
Supply Voltage (VCC)b0.5V to a7.0V
DC Input Diode Current (IIK)
VIeb
0.5V b20 mA
VIeVCC a0.5V a20 mA
DC Input Voltage (VI)b0.5V to VCC a0.5V
DC Output Diode Current (IOK)
VOeb
0.5V b20 mA
VOeVCC a0.5V a20 mA
DC Output Voltage (VO)b0.5V to VCC a0.5V
DC Output Source
or Sink Current (IO)g50 mA
DC VCC or Ground Current
per Output Pin (ICC or IGND)g50 mA
Storage Temperature (TSTG)b65§Ctoa
150§C
DC Latch-Up Source or
Sink Current g300 mA
Junction Temperature (TJ)
CDIP 175§C
PDIP 140§C
Note 1: Absolute maximum ratings are those values beyond which damage
to the device may occur. The databook specifications should be met, without
exception, to ensure that the system design is reliable over its power supply,
temperature, and output/input loading variables. National does not recom-
mend operation of FACTTM circuits outside databook specifications.
Recommended Operating
Conditions
Supply Voltage (VCC)
’AC 2.0V to 6.0V
’ACT 4.5V to 5.5V
Input Voltage (VI) 0VtoV
CC
Output Voltage (VO) 0VtoV
CC
Operating Temperature (TA)
74AC/ACT b40§Ctoa
85§C
54ACT b55§Ctoa
125§C
Minimum Input Edge Rate DV/Dt
’AC Devices
VIN from 30% to 70% of VCC
VCC @3.0V, 4.5V, 5.5V 125 mV/ns
Minimum Input Edge Rate DV/Dt
’ACT Devices
VIN from 0.8V to 2.0V
VCC @4.5V, 5.5V 125 mV/ns
Note: PLCC packaging is not recommended for applications requiring great-
er than 2000 temperature cycles from b40§Ctoa
125§C.
DC Electrical Characteristics for ’AC Family Devices
74AC 74AC
Symbol Parameter VCC TAea
25§CTAeUnits Conditions
(V) b40§Ctoa
85§C
Typ Guaranteed Limits
VIH Minimum High Level 3.0 1.5 2.1 2.1 VOUT e0.1V
Input Voltage 4.5 2.25 3.15 3.15 V or VCC b0.1V
5.5 2.75 3.85 3.85
VIL Maximum Low Level 3.0 1.5 0.9 0.9 VOUT e0.1V
Input Voltage 4.5 2.25 1.35 1.35 V or VCC b0.1V
5.5 2.75 1.65 1.65
VOH Minimum High Level 3.0 2.99 2.9 2.9 IOUT eb
50 mA
Output Voltage 4.5 4.49 4.4 4.4 V
5.5 5.49 5.4 5.4
*VIN eVIL or VIH
3.0 2.56 2.46 Vb12 mA
4.5 3.86 3.76 IOH b24 mA
5.5 4.86 4.76 b24 mA
VOL Maximum Low Level 3.0 0.002 0.1 0.1 IOUT e50 mA
Output Voltage 4.5 0.001 0.1 0.1 V
5.5 0.001 0.1 0.1
*VIN eVIL or VIH
3.0 0.36 0.44 12 mA
4.5 0.36 0.44 V IOL 24 mA
5.5 0.36 0.44 24 mA
IIN Maximum Input 5.5 g0.1 g1.0 mAVIeVCC, GND
Leakage Current (Note)
*Maximum of 9 outputs loaded; thresholds on input associated with output under test.
8
DC Electrical Characteristics for ’AC Family Devices (Continued)
74AC 74AC
Symbol Parameter VCC TAea
25§CTAeUnits Conditions
(V) b40§Ctoa
85§C
Typ Guaranteed Limits
IOLD ²Minimum Dynamic 5.5 75 mA VOLD e1.65V Max
IOHD Output Current 5.5 b75 mA VOHD e3.85V Min
ICC Maximum Quiescent 5.5 8.0 80.0 mAVIN eVCC
Supply Current or GND (Note)
IOZ Maximum TRI-STATE VI(OE) eVIL,V
IH
Leakage Current 5.5 g0.5 g5.0 mAV
I
e
V
CC, GND
VOeVCC, GND
²Maximum test duration 2.0 ms, one output loaded at a time.
Note: IIN and ICC @3.0V are guaranteed to be less than or equal to the respective limit @5.5V VCC.I
CC for 54AC @25§C is identical to 74AC @25§C.
DC Electrical Characteristics for ’ACT Family Devices
74ACT 54ACT 74ACT
Symbol Parameter VCC TAea
25§CTAeTAeUnits Conditions
(V) b55§Ctoa
125§Cb40§Ctoa
85§C
Typ Guaranteed Limits
VIH Minimum High Level 4.5 1.5 2.0 2.0 2.0 VVOUT e0.1V
Input Voltage 5.5 1.5 2.0 2.0 2.0 or VCC b0.1V
VIL Maximum Low Level 4.5 1.5 0.8 0.8 0.8 VVOUT e0.1V
Input Voltage 5.5 1.5 0.8 0.8 0.8 or VCC b0.1V
VOH Minimum High Level 4.5 4.49 4.4 4.4 4.4 VIOUT eb
50 mA
Output Voltage 5.5 5.49 5.4 5.4 5.4
*VIN eVIL or VIH
4.5 3.86 3.70 3.76 V IOH b24 mA
5.5 4.86 4.70 4.76 b24 mA
VOL Maximum Low Level 4.5 0.001 0.1 0.1 0.1 VIOUT e50 mA
Output Voltage 5.5 0.001 0.1 0.1 0.1
*VIN eVIL or VIH
4.5 0.36 0.50 0.44 VIOL 24 mA
5.5 0.36 0.50 0.44 24 mA
IIN Maximum Input 5.5 g0.1 g1.0 g1.0 mAVIeVCC, GND
Leakage Current
IOZ Maximum TRI-STATE 5.5 g0.5 g10.0 g5.0 mAVIeVIL,V
IH
Leakage Current VOeVCC, GND
ICCT Maximum ICC/Input 5.5 0.6 1.6 1.5 mA VIeVCC b2.1V
IOLD ²Minimum Dynamic 5.5 50 75 mA VOLD e1.65V Max
IOHD Output Current 5.5 b50 b75 mA VOHD e3.85V Min
ICC Maximum Quiescent 5.5 8.0 160.0 80.0 mAVIN eVCC
Supply Current or GND (Note)
*Maximum of 9 outputs loaded; thresholds on input associated with output under test.
²Maximum test duration 2.0 ms, one output loaded at a time.
Note: ICC for 54ACT @25§C is identical to 74ACT @25§C.
9
AC Electrical Characteristics
74AC 74AC
VCC*TAea
25§CTAeb
40§CFig.
Symbol Parameter (V) CLe50 pF to a85§C Units No.
CLe50 pF
Min Typ Max Min Max
tPLH Propagation Delay 3.3 2.5 12.0 15.0 2.5 15.5 ns 1
tPHL An,B
nto Bn,A
n5.0 1.5 7.0 10.0 1.5 10.5
tPLH Propagation Delay 3.3 2.5 9.5 12.0 2.5 12.5 ns 1
tPHL APAR, BPAR to BPAR, APAR 5.0 1.5 5.5 8.0 1.5 8.5
tPLH Propagation Delay 3.3 3.0 13.5 16.5 3.0 17.0 ns 2
tPHL An,B
nto BPAR, APAR 5.0 2.0 8.0 11.0 2.0 11.5
tPLH Propagation Delay 3.3 2.5 12.5 15.5 2.5 16.5 ns 3
tPHL An,B
nto ERRA, ERRB 5.0 1.5 7.5 10.5 1.5 11.0
tPLH Propagation Delay 3.3 2.5 12.5 15.5 2.5 16.5 ns 4
tPHL ODD/EVEN to ERRA, ERRB 5.0 1.5 7.5 10.5 1.5 11.0
tPLH Propagation Delay 3.3 3.0 12.5 15.5 3.0 16.5 ns 5
tPHL ODD/EVEN to APAR, BPAR 5.0 2.0 7.5 10.5 2.0 11.0
tPLH Propagation Delay 3.3 2.0 12.5 15.5 2.0 16.5 ns 6
tPHL APAR, BPAR to ERRA, ERRB 5.0 1.5 7.5 10.5 1.5 11.0
tPLH Propagation Delay 3.3 2.0 10.0 12.5 2.0 13.5 ns 9
tPHL SEL to APAR, BPAR 5.0 1.5 6.0 8.5 1.5 9.0
tPLH Propagation Delay 3.3 4.0 12.0 15.5 4.0 16.5 ns 10, 11
tPHL LEB, LEA to An,B
n5.0 2.5 7.0 10.5 2.5 11.0
tPLH Propagation Delay 3.3 3.0 13.5 17.0 3.0 18.0 ns 10, 11
tPHL LEB, LEA to APAR, BPAR 5.0 2.0 8.0 11.5 2.0 12.0
tPLH Propagation Delay 3.3 4.0 13.5 17.0 4.0 18.0 ns 12
tPHL LEB, LEA to ERRA, ERRB 5.0 2.5 8.0 11.5 2.5 12.0
tPZH Output Enable Time 3.3 3.0 12.5 15.5 3.0 16.5 ns 7, 8
tPZL GBA, GAB to An,B
n5.0 2.0 7.5 10.5 2.0 11.0
tPZH Output Enable Time 3.3 2.5 10.5 13.5 2.5 14.0 ns 7, 8
tPZL GBA, GAB to APAR, BPAR 5.0 1.5 6.0 9.0 1.5 9.5
tPHZ Output Disable Time 3.3 1.5 11.0 14.0 1.5 14.0 ns 7, 8
tPLZ GBA, GAB to An,B
n5.0 1.0 6.5 9.5 1.0 9.5
tPHZ Output Disable Time 3.3 1.5 11.0 14.0 1.5 14.0 ns 7, 8
tPHL GBA, GAB to APAR, BPAR 5.0 1.0 6.5 9.5 1.0 9.5
*Voltage Range 5.0 is 5.0V g0.5V.
Voltage Range 3.3 is 3.3V g0.3V.
10
AC Operating Requirements
74AC 74AC
VCC*TAea
25§CTAeb
40§CFig.
Symbol Parameter (V) CLe50 pF to a85§C Units No.
CLe50 pF
Guaranteed Minimum
tsSetup Time, HIGH or LOW 3.3 3.0 3.0 ns 11, 12
An,B
n
, PAR to LEA, LEB 5.0 3.0 3.0
thHold Time, HIGH or LOW 3.3 2.0 2.0 ns 11, 12
An,B
n
, PAR to LEA, LEB 5.0 1.5 1.5
twPulse Width for LEA, LEB 3.3 4.0 4.0 ns 13
5.0 4.0 4.0
*Voltage Range 5.0 is 5.0V g0.5V.
Voltage Range 3.3 is 3.3V g0.3V.
AC Electrical Characteristics
74ACT 54ACT 74ACT
VCC*TAea
25§CTAeb
55§CT
A
eb
40§CFig.
Symbol Parameter (V) CLe50 pF to a125§Cto
a
85§C Units No.
CLe50 pF CLe50 pF
Min Typ Max Min Max Min Max
tPLH Propagation Delay 5.0 2.5 7.5 11.5 1.5 13.5 2.5 12.0 ns 1
tPHL An,B
nto Bn,A
n
t
PLH Propagation Delay 5.0 1.5 6.0 8.5 1.5 11.0 1.5 9.0 ns 1
tPHL APAR, BPAR to BPAR , APAR
tPLH Propagation Delay 5.0 2.5 8.5 12.0 1.5 16.0 2.5 12.5 ns 2
tPHL An,B
nto BPAR, APAR
tPLH Propagation Delay 5.0 2.0 8.0 11.5 1.5 16.0 2.0 12.0 ns 3
tPHL An,B
nto ERRA, ERRB
tPLH Propagation Delay 5.0 2.0 8.0 11.5 1.5 16.0 2.0 12.0 ns 4
tPHL ODD/EVEN to ERRA, ERRB
tPLH Propagation Delay 5.0 2.5 8.0 11.5 1.5 14.5 2.5 12.0 ns 5
tPHL ODD/EVEN to APAR, BPAR
tPLH Propagation Delay 5.0 1.5 7.5 10.5 1.5 11.5 1.5 11.5 ns 6
tPHL APAR, BPAR to ERRA, ERRB
tPLH Propagation Delay 5.0 1.5 6.5 9.0 1.5 12.5 1.5 9.5 ns 9
tPHL SEL to APAR, BPAR
tPLH Propagation Delay 5.0 2.5 7.0 10.5 1.5 13.5 2.5 11.0 ns 10, 11
tPHL LEB to An,B
n
t
PLH Propagation Delay 5.0 2.0 8.0 11.5 1.5 16.0 2.0 12.0 ns 10, 11
tPHL LEA to APAR, BPAR
tPLH Propagation Delay 5.0 2.5 8.0 11.5 1.5 16.0 2.5 12.0 ns 12
tPHL LEA, LEB to ERRA, ERRB
tPZH Output Enable Time 5.0 2.5 7.0 10.5 1.5 16.0 2.5 11.0 ns 7, 8
tPZL GBA or GAB to An,B
n
t
PZH Output Enable Time 5.0 1.5 6.0 9.0 1.5 11.0 1.5 9.5 ns 7, 8
tPZL GBA or GAB to BPAR or APAR
tPHZ Output Disable Time 5.0 1.5 6.5 9.5 1.5 11.0 1.5 9.5 ns 7, 8
tPHL GBA or GAB to An,B
n
t
PHZ Output Disable Time 5.0 1.5 6.5 9.5 1.5 11.0 1.5 9.5 ns 7, 8
tPLZ GBA or GAB to BPAR, APAR
*Voltage Range 5.0 is 5.0V g0.5V.
11
AC Operating Requirements
74ACT 54ACT 74ACT
VCC*TAea
25§CTAeb
55§CT
A
eb
40§CFig.
Symbol Parameter (V) CLe50 pF to a125§Cto
a
85§C Units No.
CLe50 pF CLe50 pF
Guaranteed Minimum
tsSetup Time, HIGH or LOW 5.0 3.0 3.0 3.0 ns 11, 12
An,B
n
, PAR to LEA, LEB
thHold Time, HIGH or LOW 5.0 1.5 3.0 1.5 ns 11, 12
An,B
n
, PAR to LEA, LEB
twPulse Width for LEB, LEA 5.0 4.0 4.0 4.0 ns 13
*Voltage Range 5.0 e5.0V g0.5V.
Capacitance
Symbol Parameter Typ Units Conditions
CIN Input Capacitance 4.5 pF VCC e5.0V
CPD Power Dissipation 210 pF VCC e5.0V
Capacitance
Ordering Information
The device number is used to form part of a simplified purchasing code where the package type and temperature range are
defined as follows:
74ACT 899 Q C X
Temperature Range Family Special Variations
74AC eCommercial X eDevices shipped in 13×reels
74ACT eCommercial TTL-Compatible QB eMilitary grade with environmental
54ACT eMilitary TTL-Compatible and burn-in processing shipped
in tubes
Device Type
Temperature Range
Package Code CeCommercial (b40§Ctoa
85§C)
QePlastic Leaded Chip Carrier (PCC) MeMilitary (b55§Ctoa
125§C)
12
13
74AC899 #54ACT/74ACT899
9-Bit Latchable Transceiver with Parity Generator/Checker
Physical Dimensions inches (millimeters) Lit. Ý115200
28-Lead Plastic Chip Carrier (Q)
NS Package Number V28A
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL
SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or 2. A critical component is any component of a life
systems which, (a) are intended for surgical implant support device or system whose failure to perform can
into the body, or (b) support or sustain life, and whose be reasonably expected to cause the failure of the life
failure to perform, when properly used in accordance support device or system, or to affect its safety or
with instructions for use provided in the labeling, can effectiveness.
be reasonably expected to result in a significant injury
to the user.
National Semiconductor National Semiconductor National Semiconductor National Semiconductor National Semiconductores National Semiconductor
Corporation GmbH Japan Ltd. Hong Kong Ltd. Do Brazil Ltda. (Australia) Pty, Ltd.
2900 Semiconductor Drive Livry-Gargan-Str. 10 Sumitomo Chemical 13th Floor, Straight Block, Rue Deputado Lacorda Franco Building 16
P.O. Box 58090 D-82256 F4urstenfeldbruck Engineering Center Ocean Centre, 5 Canton Rd. 120-3A Business Park Drive
Santa Clara, CA 95052-8090 Germany Bldg. 7F Tsimshatsui, Kowloon Sao Paulo-SP Monash Business Park
Tel: 1(800) 272-9959 Tel: (81-41) 35-0 1-7-1, Nakase, Mihama-Ku Hong Kong Brazil 05418-000 Nottinghill, Melbourne
TWX: (910) 339-9240 Telex: 527649 Chiba-City, Tel: (852) 2737-1600 Tel: (55-11) 212-5066 Victoria 3168 Australia
Fax: (81-41) 35-1 Ciba Prefecture 261 Fax: (852) 2736-9960 Telex: 391-1131931 NSBR BR Tel: (3) 558-9999
Tel: (043) 299-2300 Fax: (55-11) 212-1181 Fax: (3) 558-9998
Fax: (043) 299-2500
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.