ETC AM79865/AM79866A

FINAL
Am79865/Am79866A
Physical Data Transmitter/Physical Data Receiver
DISTINCTIVE CHARACTERISTICS
■ Fully compliant with ANSI X3T9.5 FDDI,
TP-FDDI, and 100BASE-TX/FX PHY standards
■ The on-chip Phase-Locked-Loop (PLL) only
requires an external frequency reference
■ Provides data and clock recovery functions for
FDDI and Fast Ethernet applications
■ 125 MBaud (100 Mbps) serial link data rate
■ Parallel input to the PDT is a 5-bit encoded NRZ
symbol clocked by LSCLK
■ Parallel output from the PDR is a 5-bit
unframed NRZ symbol clocked by RSCLK
■ Dedicated pins provide electrical loopback
data path
■ 20-pin Plastic Leaded Chip Carrier (PLCC)
■ Single +5 V power supply operation
■ Interfaces to fiber or copper media
GENERAL DESCRIPTION
The Physical Data Transmitter (Am79865) and the
Physical Data Receiver (Am79866) devices provide
clock recovery/generation functions meeting the requirements of FDDI, TP-FDDI, and 100BASE-TX PHY
standards.
The PDT and PDR devices are part of the SUPERNET
2 FDDI Physical Layer Protocol chip set which also includes the Physical Layer Controller with Scrambler
(PLC-S). The PLC-S (Am79C864A), PDT and PDR devices are collectively known as the AmPHY. The PLC-S
performs the FDDI physical layer functions which
includes, among others, the 4B5B encoding and
decoding.
The PDT converts encoded symbols into a serial NRZI
data stream. The on-chip PLL generates a bit rate clock
from the LSCLK reference.
The PDR uses a built-in clock recovery PLL to extract
clock information from the received data stream. The
recovered clock is used for serial-to-parallel data
conversion.
Publication# 15451 Rev: D Amendment/0
Issue Date: June 1996
BLOCK DIAGRAM
Am79865 PDT
LPBCK
TDAT 4-0
Input Register
Output
Control
NRZ
Shifter
Test Mode
Sync Logic
LSCLK
LTX, LTY
NRZI
÷5
Clock Multiplier
(PLL)
Output
Control
TEST
FOTOFF
TX, TY
15451D-1
Am79866A PDR
RDAT 4-0
RSCLK
Output Register
Shifter
NRZ
NRZI
Clock
Recovery
PLL
÷5
TEST
LSCLK
SDO
Q
D
Media Interface
LSCLK
SDI
LRX, LRY
2
RX, RY
Am79865/Am79866A
15451D-2
CONNECTION DIAGRAMS
Top View
RDAT2
GND1
16
15
14
8
LTX
VCC1
GND1
NC
VCC1
RDAT3
RDAT4
GND2
4
5
6
TEST
7
LPBCK
8
TY
TX
RSCLK
Am79866A 16
15
PDR
VCC2
SDO
LSCLK
14
GND1
9 10 11 12 13
9 10 11 12 13
NC
18
17
LRY
LRX
RY
7
Am79865
PDT
TEST
VCC2
LSCLK
18
17
FOTOFF
TDAT0
4
5
6
15451D-3
Am79865/Am79866A
RX
SDI
TDAT4
TDAT2
TDAT3
LPBCK
LTY
3 2 1 20 19
3 2 1 20 19
GND2
TDAT1
RDAT1
VCC1
RDAT0
20-Pin PLCC
20-Pin PLCC
15451D-4
3
LOGIC SYMBOLS
Am79C864A PLC-S Interface
Parallel Data Symbol
TDAT 4–0
25 MHz
Local Symbol
Clock
Test Mode Select
Forcing Optical
Transmitter Off
Loopback
Control
FOTOFF
LPBCK
LTX, LTY
Am79865
PDT
LSCLK
TEST
Data Loopback
to Local PDR
TX, TY
Serial Data Transmitted in
NRZI Format
Note:
Three VCC pins and two GND pins.
Fiber or Copper Interface
15451D-5
Am79C864A PLC-S Interface
Parallel Data
Symbol
RDAT 4–0
25 MHz
Local Symbol
Clock
Test Mode Select
Note:
Two VCC pins and three GND pins.
4
LSCLK
TEST
Recovered Light
Symbol
Level
Clock
Signal
RSCLK
Loopback
Control
SDO
Am79866A
PDR
LPBCK
LRX, LRY
RX, RY
SDI
Serial Data Received
in NRZI Format
Light
Level
Signal
Fiber or Copper Interface
Am79865/Am79866A
Data Loopback
from Local PDT
15451D-6
ORDERING INFORMATION
Standard Products
AMD standard products are available in several packages and operating ranges. The order number (Valid Combination) is formed
by a combination of the elements below.
AM79865/
AM79866A
J
C
TEMPERATURE RANGE
C = Commercial (0°C to +70°C)
PACKAGE TYPE
J = 20-Pin Plastic Leaded Chip Carrier
(PL 020)
SPEED OPTION
Not Applicable
DEVICE NUMBER/DESCRIPTION
Am79865 = Physical Data Transmitter
Am79866A = Physical Data Receiver
Valid Combinations
AM79865
JC
AM79866A
Valid Combinations
Valid Combinations list configurations planned to be supported in volume for this device. Consult the local AMD sales
office to confirm availability of specific valid combinations and
to check on newly released combinations.
Am79865/Am79866A
5
Am79865 PDT PIN DESCRIPTION
TDAT 4–0
TX, TY**
Transmit Data (TTL Inputs)
Transmit Data (PECL Differential Outputs)
These five inputs accept data symbols from the
Am79C864 PLC, latched by the rising edge of LSCLK.
These transmit outputs carry differential NRZI data.
They can be forced to logical 0 (TX LOW, TY HIGH) by
asserting the FOTOFF input.
LSCLK
Local Symbol Clock (TTL Input)
LTX, LTY**
This pin supplies the frequency and phase reference to
the internal PLL clock multiplier. It should be driven by
an external 25 MHz crystal-controlled clock source.
Loopback
Outputs)
FOTOFF
Fiber Optic Transmitter Off (TTL Input, active LOW)
When held LOW, the TX output is forced LOW and TY
output is forced HIGH so that the Fiber Optic Transmitter will output logical 0. In test mode, FOTOFF is used
as the test clock input and does not control TX/TY.
LPBCK
Loopback Control (TTL Input, active LOW)
When asserted, the LTX/LTY outputs transmit the NRZI
serial bit stream to the PDR to establish the loopback
data path. When deasserted, the LTX output is forced
LOW and LTY output is forced HIGH.
TEST
Test Mode Enable (TTL Input)
When asserted, the PDT is in Test mode. For normal
operation, TEST pin must be tied LOW.
Transmit
Data
(PECL
Differential
These differential outputs carry the same signal as TX/
TY when the LPBCK input is asserted (LOW). LTX/LTY
should be connected to the LRX/LRY pins of
Am79866A PDR to perform loopback function. When
LPBCK is deasserted (HIGH), LTX is forced LOW and
LTY is forced HIGH.
**All differential PECL outputs carry data at ECL voltage levels referenced to +5.0 V (PECL levels). The external terminations required are shown in the Interface
Connection Diagram in the Appendix.
VCC1, VCC2
Power Supply
VCC1,VCC2 are +5.0 V nominal power supply pins. VCC1
powers all TTL and ECL I/O circuits. VCC2 powers all internal logic gates and analog circuits. They must be
connected to a common external supply.
GND1, GND2
Ground Pins
GND1 is TTL and ECL I/O ground. GND2 is the internal
logic and analog ground. They must be connected to a
common external ground reference.
6
Am79865/Am79866A
Am79866A PDR PIN DESCRIPTION
LSCLK
SDO
Local Symbol Clock (TTL Input)
Signal Detect Output (TTL Output)
LSCLK is driven by an external frequency source at the
25 MHz symbol rate. This signal is used as a frequency
reference for the PDR clock-recovery PLL.
SDO is the SDI input synchronized by LSCLK. It has
the same logical sense as SDI, i.e., HIGH indicates the
received optical signal is above the detection threshold.
LPBCK
RX, RY*
Loopback (TTL Input, active LOW)
Received Data (PECL Differential Line Receiver
Inputs)
When active, LPBCK selects the serial data stream at
LRX/LRY inputs as the received data. When HIGH, RX/
RY are selected. This function is used during system
loopback test to bypass the transmission medium.
TEST
TEST Mode Enable (TTL Input)
When asserted, the PDR is in Test mode. For normal
operation, TEST pin must be tied LOW.
RDAT 4–0
Received Data (TTL Outputs)
These 5-bit parallel outputs are clocked by the falling
edge of RSCLK and carry the NRZ data symbols to the
PLC.
RSCLK
Recovered Symbol Clock (TTL Output)
RSCLK is derived from the clock synchronization PLL
circuit. It is synchronous to the received serial data,
and is the recovered bit clock divided-by-five. This is a
25 MHz clock.
SDI
Signal Detect Input (PECL Single-Ended Input)
SDI typically comes from the fiber optic receiver to indicate that the received optical signal is above the detection threshold. When asserted (HIGH), the data on RX/
RY are used for the input to the PDR. When deasserted
(LOW), the RX/RY data stream is gated off and the PLL
locks onto the LSCLK.
These pins receive NRZI data.
LRX, LRY*
Loopback Received Data (PECL Differential Line
Receiver Inputs)
This input pair should be connected to the PDT LTX/
LTY outputs through properly terminated lines to establish the loopback data path. When LPBCK is asserted,
LRX/LRY carry the data to be used as the input to the
PDR. In Test mode, LRX/LRY become the test clock
input.
*RX/RY and LRX/LRY are differential line receivers
which have high input sensitivity and wide
common-mode range. They can also accept PECL
voltage swings and shall be driven by properly terminated transmission lines.
VCC1, VCC2
Power Supply
VCC1,VCC2 are +5.0 V nominal power supply pins. VCC1
powers all TTL and ECL I/O circuits. VCC2 powers all internal logic gates and analog circuits. They must be
connected to a common external supply.
GND1, GND2
Ground Pins
GND1 is TTL and ECL I/O ground. GND2 is the internal
logic and analog ground. They must be connected to a
common external ground reference.
Am79865/Am79866A
7
FUNCTIONAL DESCRIPTION
Normal Operation Mode
The Am79865 PDT accepts encoded data symbols at
TDAT 4–0 pins. The 5-bit symbol is latched into the
PDT by the rising edge of LSCLK, serialized, converted
to NRZI format and shifted to the outputs (TDAT4 bit is
transmitted first). There are two pairs of serial data outputs capable of driving either Fiber Optic Interface
hardware or wire transmission lines without external
buffering. The TX/TY pair is connected to the serial link
and the LTX/LTY pair is used in the loopback connection to the Am79866A PDR.
The PDT uses LSCLK as the frequency reference to
generate the serial link data rate. The external clock
source must be crystal controlled and continuous. All of
the internal logic of PDT runs on an internal clock that
is PLL-multiplied from the external reference source.
The PDT’s internal PLL is referenced to the rising
edges of LSCLK only.
The input clock frequency required to achieve
125 MBaud on the serial link is 25 MHz at LSCLK. In
order to generate the serial output waveforms conforming to the FDDI specification, the external reference
clock (LSCLK) must meet FDDI frequency and stability
requirements. The PDT serial output typically contains
less than 0.4 ns peak-to-peak jitter at 125 MBaud. The
latency from the LSCLK to the serial output is typically
4 to 6 bits (8 ns/bit).
The Am79866A PDR accepts encoded NRZI serial
data on the RX/RY inputs and converts them to NRZ
format. It then latches the unframed symbol (5 bits) to
the RDAT 4-0 outputs on the falling edge of RSCLK.
T h e h e a rt o f t h e A m 7 9 8 6 6 A P D R c h i p i s i t s
clock-recovery PLL which extracts encoded clock information from the serial NRZI data stream and recovers
the data. The PLL examines every data transition in the
8
received serial stream and aligns its internal bit clock
with these data transitions. In order to guarantee the
correct operation of the PLL, the encoding scheme
(such as the FDDI 4B5B code) must insure adequate
transition density of the encoded data stream.
The PDR has input jitter tolerance characteristics that
meet or exceed the recommendations of Physical
Layer Medium Dependent (PMD) FDDI document. Typically, at 125 MBaud (8 ns/bit), the peak-to-peak
Duty-Cycle Distortion (DCD) tolerance is 1.4 ns, the
peak-to-peak Data-Dependent Jitter (DDJ) tolerance is
2.2 ns, and the peak-to-peak Random Jitter (RJ) tolerance is 2.27 ns. The total combined peak-to-peak jitter
tolerance is typically 5 ns with bit error rate (BER) less
than 2.5 x 10–10.
The PDR’s PLL typically has an acquisition time of 100
µs or less when ‘Master’ symbols (one data transition
within ten bits) are received. The acquisition time reduces with increasing transition density in the data
stream.
The SDI input qualifies the data at RX/RY. When SDI is
LOW, the PDR uses LSCLK as the PLL input and
forces LOW at the Output Register. The LPBCK input
selects the data source between RX/RY and LRX/LRY.
When LPBCK is LOW, the SDI input is ignored.
When SDI is HIGH and the RX/RY input stream contains no data transition for PLL input, the PLL operating
frequency range is limited by the LSCLK reference. The
observed RSCLK output frequency is generally within
0.5% of the LSCLK frequency.
Under normal conditions, the frequency of LSCLK multiplied by five must be within 0.25% of the expected received data for the PLL to operate correctly. (Note,
FDDI specifies the two frequencies to be within 50 ppm
or 0.005% of each other.)
Am79865/Am79866A
Am79865 PDT Functional Block
Description
accept the encoded NRZI serial data. LRX/LRY are
also differential line receiver inputs which accept the
loopback data stream from the local PDT LTX/LTY
outputs.
Clock Multiplier
LSCLK supplies the reference frequency which is multiplied by five using an on-chip PLL. The transmission
rate and all serialization logic are controlled by the
internally generated bit clock.
Input Register
TDAT 4–0 are clocked into the Input Register by the rising edge of LSCLK.
Shifter
Parallel data are loaded from the Input Register into the
Shifter at the internally generated symbol boundary,
and serially shifted at the bit clock rate.
NRZ-to-NRZI Converter
The NRZ output of the Shifter is converted into NRZI
data patterns for transmission.
Output Control
The differential outputs carry the encoded serial NRZI
bit stream. The TX/TY pair can be forced to logical 0
(TX LOW, TY HIGH) by asserting FOTOFF input. The
LTX/LTY pair can be forced to logical 0 (LTX LOW, LTY
HIGH) by deasserting the LPBCK input.
Am79866A PDR Functional Block
Description
Clock-Recovery PLL
The clock-recovery PLL separates the input data
stream into clock and data patterns. The PLL operating
frequency is established by the reference at LSCLK.
The PLL is capable of tracking data correctly within +
0.25% of LSCLK (exceeds the frequency range defined
by the FDDI specification).
Media Interface
NRZI-TO-NRZ Converter
Serial data are retimed and associated jitter is removed. Retimed data are converted into NRZ format
prior to the Shifter input.
Shifter
The Shifter is serially loaded from the NRZI_TO_NRZ
converter, using the recovered bit clock.
Output Register
The Output Register is clocked by RSCLK falling edges.
RSCLK is the recovered bit clock divided-by-five and is
synchronous to the received serial data.
Test Mode
Asserting PDT TEST input pin forces PDT into its test
mode. This allows testing of the internal logic without
the PLL clock multiplier. The internal clock source is replaced by the test clock provided at the FOTOFF input.
An automatic test system can clock the PDT through
functional test patterns at any rate, typically less than
25 MHz, or any sequence to facilitate logic verification.
In PDT test mode, LSCLK strobes data into the Input
Register and provides initialization to the internal
counter.
The PDR test mode allows testing of the internal logic
without the PLL. When TEST is HIGH, the internal
clock source is replaced by the test clock provided at
the LRX/LRY inputs. Note: The loopback data path in
the Am79866A PDR cannot be tested in test mode.
An automatic test system can clock the PDR through
functional test patterns at any rate, typically less than
25 MHz, or any sequence to facilitate logic verification.
The RX/RY inputs are typically driven by differential
PECL voltages, referenced to +5 V. These inputs
Am79865/Am79866A
9
ABSOLUTE MAXIMUM RATINGS
OPERATING RANGES
Storage Temperature . . . . . . . . . . . . –65°C to +150°C
Commercial (C) Devices
Ambient Temperature Under Bias . . . . . . 0°C to 70°C
Ambient Temperature (TA). . . . . . . . . . . . .0°C to 70°C
Supply Voltage (VCC) . . . . . . . . . . +4.75 V to +5.25 V
Supply Voltage (VCC) to
Ground Potential Continuous . . . . . . . –0.5 V to +7.0 V
DC Voltage Applied to Outputs. . . . . .–0.5 to VCC Max
Operating ranges define those limits between which the
functionality of the device is guaranteed.
DC Input Voltage . . . . . . . . . . . . . . . . –0.5 V to +5.5 V
DC Output Current . . . . . . . . . . . . . . . . . . . . . . .±100 mA
DC Input Current . . . . . . . . . . . . . –30 mA to +5.0 mA
Stresses above those listed under Absolute Maximum
Ratings may cause permanent device failure. Functionality at or
above these limits is not implied. Exposure to Absolute Maximum
Ratings for extended periods may affect device reliability.
DC CHARACTERISTICS over COMMERCIAL operating ranges unless otherwise specified
Am79865 PDT
Parameter
Symbol
Parameter Description
Test Description
Min
Max
TTL Inputs: TDAT 4–0, LSCLK, FOTOFF, LPBCK, TEST
VIH
Input HIGH Voltage
VCC = Max (Note 2)
2.0 V
VIL
Input LOW Voltage
VCC = Max (Note 2)
0.8 V
VI
Input Clamp Voltage
VCC = Min, IIN = –18 mA
–1.5 V
IIH
Input HIGH Current
VCC = Max, VIN = 2.7 V
50 µA
IIL
Input LOW Current
VCC = Max, VIN = 0.4 V
–400 µA
II
Input Leakage Current
VCC = Max, VIN = 5.5 V
50 µA
PECL Outputs: TX, TX; LTX, LTY
VOH
Input HIGH Voltage
PECL Load (Note 3)
VCC – 1.025 V
VCC – 0.88 V
VOL
Input LOW Voltage
PECL Load (Note 3)
VCC – 1.81 V
0.8VCC – 1.62 V
Power Supplies
10
ICC1
VCC1 Supply Current
VCC1 = VCC2 = Max (Note 4)
20
ICC2
VCC2 Supply Current
VCC1 = VCC2 = Max
65
Am79865/Am79866A
DC CHARACTERISTICS over COMMERCIAL operating ranges unless otherwise specified
Am79866 PDT
Parameter
Symbol
Parameter Description
Test Description
Min
Max
TTL Inputs: LSCLK, LPBCK, TEST
VIH
Input HIGH Voltage
VCC = Max (Note 2)
VIL
Input LOW Voltage
VCC = Max (Note 2)
0.8 V
VI
Input Clamp Voltage
VCC = Min, IIN = –18 mA
–1.5 V
IIH
Input HIGH Current
VCC = Max, VIN = 2.7 V
50 µA
IIL
Input LOW Current
VCC = Max, VIN = 0.4 V
–400 µA
II
Input Leakage Current
VCC = Max, VIN = 5.5 V
50 µA
2.0 V
TTL Outputs: RDAT 4–0, SDO, RSCLK
VOH
Output HIGH Voltage
VCC = Min, IOH = –1 mA
2.4 V
VOL
Output LOW Voltage
VCC = Min, IOL = 4 mA
ISC
Output Short Circuit Current
VCC = Max (Note 5)
–15 mA V
–85 mA
0.45 V
Differential PECL Inputs: RX, RY; LRX, LRY
VIN
Input Voltage
(Absolute High or Low)
VCC = Max (Note 2)
2.5 V
VCC
Vdif
Input Differential Voltage
VCC = Max (Note 2, 6)
50 mV
1.1 V
IIH
Input HIGH Current
VCC = Max, VIN = VCC – 0.88 V
IIL
Input LOW Current
VCC = Max, VIN = VCC – 1.81 V
220 µA
0.5 µA
Single-Ended PECL Input: SDI
VIHS
Input Single-Ended HIGH Voltage
VCC = Max (Note 2, 7)
VCC – 1.165 V
VCC – 0.88 V
VILS
Input Single-Ended LOW Voltage
VCC = Max (Note 2, 7)
VCC – 1.81 V
VCC – 1.475 V
IIH
Input HIGH Current
VCC = Max, VIN = VCC – 0.88 V
IIL
Input LOW Current
VCC = Max, VIN = VCC – 1.81 V
220 µA
0.5 µA
Power Supplies
ICC1
VCC1 Supply Current
VCC1 = VCC2 = Max
25
ICC2
VCC2 Supply Current
VCC1 = VCC2 = Max
145
Am79865/Am79866A
11
SWITCHING CHARACTERISTICS over operating range unless otherwise specified
Am79865 PDT
No.
Parameter
Symbol
1
tP
2
Parameter Description
Test Conditions (Note 8)
Min
Max
Unit
LSCLK Period
40
40
ns
tPW
LSCLK Pulse Width HIGH
15
ns
3
tPW
LSCLK Pulse Width LOW
15
ns
4
tS
TDAT 4–0 to LSCLK Rise Setup Time
12
ns
5
tH
TDAT 4–0 to LSCLK Rise Hold Time
2.5
ns
6
tR†
TX, TY, LTX, LTY Rise Time
PECL load
0.3
3
ns
7
tF†
TX, TY, LTX, LTY Hold Time
PECL load
0.3
3
ns
8
tSK†
TX/TY, LTX/LTY Skew
PECL load
±200
ps
Max
Unit
±0.25
%
Am79866A PDR
No.
Parameter
Symbol
21
fOS
LSCLK to received data frequency offset
22
tPW
LSCLK Pulse Width HIGH
15
ns
23
tPW
LSCLK Pulse Width LOW
16
ns
24
tPW
RSCLK Pulse Width HIGH
TTL load (Note 10)
10
ns
25
tPW
RSCLK Pulse Width LOW
TTL load (Note 10)
20
ns
26
tPD
RDAT4–0 Valid to RSCLK Rise
TTL load (Note 11)
13
ns
27
tPD
RSCLK Rise to RDAT4–0 Invalid
TTL load (Note 11)
10
ns
28
tS
SDI to LSCLK Rise Setup Time
5
ns
29
tH
SDI to LSCLK Rise Hold Time
7
ns
30
tPD
LSCLK Rise to SDO Delay
Parameter Description
Test Conditions (Note 8)
Min
(Note 9)
TTL load
30
ns
Notes:
1. For conditions shown as Min or Max, use the appropriate values specified under operating range.
2. Typically measured with device in Test mode while monitoring output logic states.
3. Tested for VCC = Min, shown limits are specified over entire VCC operating range.
4. PDT ICC1 is tested with all PECL outputs terminated to VCC (unloaded). The PECL outputs contribute 25 mA/pair nominally
to ICC1 when they are loaded with PECL loads, 50 Ω to (VCC – 2). In calculating the chip power dissipation, the contribution
by the output loads shall be multiplied by 1 V instead of by VCC.
5. Not more than one output should be shorted at a time. Duration of the short circuit test should not exceed one second.
†
12
Not included in the production test.
Am79865/Am79866A
Notes (continued):
6. Vdif is tested with each input voltage within the VIN range.
7. Device thresholds on the SDI pin are verified during production test by ensuring that the input threshold is less than VIHS (min)
and greater than VILS (Max). The figure below shows the acceptable range (shaded area) for the transition voltage.
V
(max)
VCC – 0.88 V
(min)
VCC – 1.165 V
VIHS
input threshold
transition voltage
VCC – 1.475 V
(max)
VILS
(min)
VCC – 1.81 V
8. All timing references are made with respect to + 1.5 V for TTL-level signals or to the 50% point between VOH and VOL for PECL
signals. PECL input rise and fall times must be 2 ns + 0.2 ns between 20% and 80% points. TTL input rise and fall times must
be 2 ns between 1 V and 2 V.
9. Received data frequency is determined by serial data inputs. Multiply LSCLK frequency by 5 to convert the receive data bit
rate.
10. Tested for 125 MBaud received data rate (1 bit-time is 8 ns). tPW (HIGH) is functionally 2 bit-time wide. tPW (LOW) is
functionally 3 bit-time wide.
11. Tested for 125 MBaud received data rate (1 bit-time 8 ns).
Am79865/Am79866A
13
SWITCHING WAVEFORMS
Am79865 PDT
1
LSCLK
3
2
4
5
Symbol k
Valid
TDAT 4–0
Symbol
k+1
Latency
TX, TY
LTX, LTY
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Symbol k
Bit 4 corresponds
to TDAT4
VOH
6
TX, TY
LTX, LTY
7
80%
20%
VOL
TX
50%
8
TY
50%
15451D-7
Am79866A PDR
RSCLK
24
25
27
RDAT 4–0
LSCLK
24
26
Parallel 5-Bit
Symbol Valid
22
27
Parallel 5-Bit
Symbol Valid
Parallel 5-Bit
Symbol Valid
23
28
29
SDI
(PECL)
30
SDO
15451D-8
14
Am79865/Am79866A
KEY TO SWITCHING WAVEFORMS
WAVEFORM
INPUTS
OUTPUTS
Must be
Steady
Will be
Steady
May
Change
from H to L
Will be
Changing
from H to L
May
Change
from L to H
Will be
Changing
from L to H
Don’t Care,
Any Change
Permitted
Changing,
State
Unknown
Does Not
Apply
Center
Line is HighImpedance
“Off” State
KS000010-PAL
SWITCHING TEST CIRCUITS
VCC
R1
VOUT
VOUT
3 pF
50 Ω
30 pF
2.4 K
VCC – 2 V
TTL Output Load
15451D-9
PECL Output Load
15451D-10
Notes:
1. CL = 30 pF includes scope probe, wiring and stray
capacitances without device in text fixture.
Notes:
1. R1 = 1 KΩ for the IOL = 4 mA
2. All diodes IN916 or IN3064, or equivalent.
3. CL = 30 pF includes scope probe, wiring and stray
capacitances without device in text fixture.
4. AMD uses constant current (A.T.E.) load configurations
and forcing functions. This figure is for reference only.
2. AMD uses Automatic Test Equipment (A.T.E.) load
configurations and forcing functions. This figure is for reference only.
Am79865/Am79866A
15
SWITCHING TEST WAVEFORMS
3.0 V
VCC – 0.9 V
80%
2.0 V
1.5 V
1.0 V
50%
20%
VCC – 1.7 V
0.0V
2 ± 0.2 ns
2 ± 0.2 ns
2 ± 0.2 ns
2 ± 0.2 ns
15451D-11
15451D-10
TTL Input Waveform
16
ECL Input Waveform
Am79865/Am79866A
PHYSICAL DIMENSIONS
Am79865/Am79866A Physical Data Transmitter/Data Receiver
PL 020
20-Pin Plastic Leaded Chip Carrier (measured in inches)
.385
.395
.042
.056
.350
.356
.062
.083
Pin 1 I.D.
.385
.395
.350
.356
.200 .290
REF .330
.013
.021
.026
.032
.009
.015
.050 REF
TOP VIEW
.090
.120
.165
.180
SEATING PLANE
SIDE VIEW
16-038-SQ
PL 020
DF79
2-20-96 lv
Trademarks
Copyright © 1996 Advanced Micro Devices, Inc. All rights reserved.
AMD, the AMD logo, and combinations thereof are trademarks of Advanced Micro Devices, Inc.
Product names used in this publication are for identification purposes only and may be trademarks of their respective companies.
Am79865/Am79866A
17