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MA1916 MA1916
Radiation Hard Reed-Solomon & Convolution Encoder
Replaces June 1999 version, DS3590-4.0 DS3590-5.0 January 2000
The purpose of the MA1916 is to encode serial data to allow error correction when the data is transmitted over a noisy communication link. As the name suggests, the unit contains two encoding elements. The Reed-Solomon encoder appends a checksum to a block of data, guarding against burst errors in a message. The convolution encoder continuously creates two code bits for each data bit it receives, increasing the noise immunity by doubling the band width of the message. The unit also contains a test pattern generator which can be connected to check the functionality of the RS encoder and to provide a message timing signal (SMC_OUT). Protection against a long error-burst can be increased by interleaving a number of message packets passing through the RS encoder. The MA1916 provides pin selectable interleave depths of 1, 4 or 5. Interleave depths of greater than 5 do not significantly improve performance. The MA1916 is designed to conform to the CCSDS standard for telemetry 101.0.B.2. It is manufactured in a radiation hard low power CMOS technology. This makes it ideal for use in satellite communications systems. The encoder reduces the risk of data corruption and allows the designer to minimize the transmitter power needed to establish an effective communications link.
FEATURES
s Radiation Hard CMOS-SOS Technology s Low Power Consumption s Latch-up Free s High SEU Immunity s CCSDS Standard RS (255, 223) s Selectable Interleave Depths of 1, 4 or 5 s 5MBit/sec Input Data Rate
Figure 1: Block Diagram
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MA1916
OPERATION
REED-SOLOMON ENCODER The function of the Reed-Solomon (RS) encoder is to take a block of 223 bytes of serial data and to append a checksum of 32 bytes. The purpose of the checksum is to allow error correction within the data block. One important feature of the Reed-Solomon algorithm is that it allows correction of a burst error which corrupts upto 16 consecutive bytes. If a number of messages are interleaved this length can be increased. The MA1916 provides pin selectable interleave depths of 1, 4 or 5 blocks (see Table 1), each of 223 bytes. An interleave depth of 5 is the maximum recommended by the CCSDS standard. This will allow correction of up to 80 sequencial bytes in a data packet. The RS encoder operates from a clock input CLK which must be driven at twice the input data rate. Internally CLK is divided to give a clock CLKS which runs at half the frequency. This signal is available as an output and is used to time data into the RS encoder. A high input on SMC is used to tell the RS encoder that data to be encoded is present on the MSG pin (see Figure 2). While SMC is high the data on MSG is buffered and appears on RSE_OUT as well as being clocked into the encoder. As soon as SMC goes low the checksum is clocked out of the encoder onto RSE_OUT. While SMC is high the RSE_OUT signal follows the input MSG. When SMC is low RSE_OUT is produced from the exclusive-OR of MSG and the checksum signal. For this reason MSG must be held low while the encoder outputs the checksum. A gap can be left between successive data packets by holding SMC and MSG low after the checksum has been sent. Alternatively, synchronisation code can be inserted before a data block by holding SMC low and placing the code on MSG. As soon as SMC goes high any further data on MSG is assumed to form part of a message and will be encoded accordingly. Note: External logic must guarantee the SMC is high for the correct period, ie only while 223 x I bytes (I = interleave depth) of data are clocked through. Otherwise when SMC falls an invalid checksum will be produced.
SEL_A
SEL_B
Interleave I = Depth
SMC_OUT Period (Bytes) SMC_OUT = 1 SMC_OUT = 0 5 x 223 4 x 223 1 x 223 5 x 223 5 x 32 4 x 32 1 x 32 5 x 32
0 0 1 1
0 1 0 1
5 4 1 5
Table 1: Interleave Length Defined by SEL_A and SEL_B
I = Interleave depths of 1, 4 or 5 SYNC: If SMC is low and no checksum is being output any data on MSG will appear on RSE_OUT. This feature can be used to insert a synchronisation sequence before a data block. DATA: Data block 223 x I bytes in length. CHECKSUM: The checksum is 32 x I bytes long and appended to the data by the RS encoder.
Figure 2: Reed-Solomon Encoder Operation
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MA1916
CONVOLUTION ENCODER The convolution encoder generates 2 serial bits of output data for each bit it reads in. The coding operates cyclically over a length of 7 bits. It increases the bandwidth of the signal but establishes a correlation between succesive bits in the output signal. The convolution encoder operates continuously using CE_CLK to read data in on CE_IN and to write the encoded data to CE_OUT. If required the output of the Reed-Solomon encoder can be fed directly into the convolution encoder by connecting RSE_OUT to CE_ IN and CLKS to CE_CLK.
TEST GENERATOR The MA1916 contains its own built-in test pattern generator, this can be connected to the RS encoder for in service testing. The test generator supplies test patterns and the SMC signal according to the inputs on T0-2 (see Table 2) and the interleave depth selected using SEL_A and SEL_B. Figure 3 shows the necessary connections for feeding test patterns through both the RS and the convolution encoder.
Figure 3: Test Configuration
Interleave Depth T2 0 0 0 0 1 T1 0 0 1 1 0 Other T0 0 1 0 1 0 Test N/A 1 2 3 4 N/A I = 5 (1115 bytes) I = 4 (892 bytes) I = 1 (223 bytes) 0 (1) x 223 (0) x 222, 7B (0) x 222, 7B (0) x 222, 7B
(1, 2, 3, 4, 5) x 223 (0) x 222 x 5, (0) x 4, (7B) (0) x 222 x 5, (7B, AF, 99, FA, B7) (0) x 221 x 5, (7B) x 5, (47) x 5
(1, 2, 3, 4) x 223 (0) x 222 x 4, (0) x 3, (7B) (0) x 222 x4, (7B, AF, 99, FA) (0) x 221 x 4, (7B) x 4, (47) x 4
Table 2: Test Pattern on MSG_OUT Defined by T0-2
PIN DESCRIPTION
VDD and GND (Power and Ground) The MA1916 uses a single power supply of 5V 10%. CLK (Clock) This input supplies a clock signal to the RS encoder and the Test generator. It requires a signal with a nominal 50% duty cycle running at twice the input data rate for the RS encoder. The rising edge of CLK is used to generate the internal CLKS signal which clocks data through the RS encoder. n_RST (Reset) This active low signal is a reset supplied to the RS encoder, the test generator and the convolution encoder. It should be noted that the reset does not clear the check sum in the RS encoder and a complete dummy data packet should be run through before valid data is sent. SEL_A and SEL_B (Interleave Depth Select) These inputs define the interleave depth of a message passing through the RS encoder They also specify the message length to be produced by the test generator (see Table 1). The inputs are connected to internal pulldown resistors. T0-2 (Test Pattern Select) These inputs select the pattern to be produced by the test generator (see Table 2). Each input is connected to an internal pull-down resistor. T3 (Production Test Input) This input is used for production testing only It has an internal pull-down resistor and should be left unconnected . MSG_OUT (Test Message Output) This output pin carries the test patterns defined by the inputs To-2 and produced by the test generator. This signal can be connected directly to MSG for testing purposes.
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MA1916
SMC_OUT (Select Message or Checksum) This output signal is held high while the test generator clocks out a data packet on the MSG_OUT pin. When the packet is complete this signal goes low. It is held low for a period equal to the time required by the RS encoder to send the corresponding checksum. When this is complete the signal goes high and the test generator begins a new data packet. This signal can be connected directly to SMC for testing purposes. READY (Test Data Valid) This output is held low during reset and remains low for the first complete cycle of SMC_OUT. READY rises on the second rising edge of SMC_OUT and remains high to indicate the presence of valid data on MSG_OUT. CLKS (Synchronisation Clock) This output clock runs at half the speed of the input clock CLK. CLKS remains low after n_RST is raised until SMC is raised, SMC being captured on the falling edge of CLK (timing 4). CLKS then changes state on the rising edge of each CLK cycle regardless of the state of SMC. The signal is used to clock data into and out of the RS encoder. MSG (Message) MSG is the data input to the RS encoder. Each bit is read in on the rising edge of CLKS. While the SMC signal is high data on the input passes directly to the output RSE_OUT. While SMC is low RSE_OUT is the logical XOR of the MSG input and the output of the check-sum generator. Therefore MSG must be held low while the RS encoder is clocking out the check sum (see Figure 4). SMC (Select Message or Checksum) While the SMC input is high, data on the MSG pin is clocked into the RS encoder. SMC is held high for a period dictated by the interleave depth being used (see Table 1). When SMC falls the RS encoder begins to clock out the checksum for the preceeding data. SMC should be held low until the complete checksum has been output. The rising edge of SMC indicates the start of a new data block to be encoded. RSE_OUT (Reed-Solomon Encoder Output) This signal outputs the completed data packet comprised of the message followed by its associated checksum block. The data is valid on the rising edge of CLKS.
Figure 4: Reed-Solomon Encoder
ST1 (RS Encoder Output Valid) This output is set low during a reset and goes high when sufficient dummy data has been clocked through the RS encoder to clear it (see Figure 5). SYZ (Byte Rate Clock) SYZ is a byte rate clock output derived from CLKS. It is high during every eighth period of CLKS and low at other times. SZY (Byte Rate Clock) SZY is a byte rate clock output derived from CLKS. It is low during every eighth period of CLKS and high at other times. It is the inverse of SYZ. ST2 (Production Test Output) The output is used for production testing and should be left unconnected. TEST_POINT (Production Test Output) This output is used for production testing and should be left unconnected. CE_IN (Convolution Encoder Data In) This input is used to read data into the convolution encoder. The state of CE_IN is read on the rising edge of CE_CLK.
n_RST SMC MSG CLKS ST1
Output Valid Note: ST1 rises on the second rising edge of SMC following n_RST high. CLKS starts toggling on the first rising edge of SMC following n_RST high.
Figure 5: Reed-Solomon Encoder Operation
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MA1916
CE_CLK (Convolution Encoder Clock) The CE_CLK input drives the timing of the convolution encoder. Data is read in on CE_IN on the rising edge of CE_CLK and output on CE_OUT on both the rising and falling edge of CE_CLK. Note: The output data rate is twice the input data rate. A 50% duty cycle clock is required. If this is provided by the CLKS output, data can be read directly from RSE_OUT to the CE_IN input (see figure 3). CE_OUT (Convolution Encoder Output) This signal carries the output data from the convolution encoder. The data rate on CE_OUT is twice that of CE_IN. CLK_OUT (Clock Out) CLK_OUT is a buffered output of the CLK input signal. If CLKS is connected to CE_CLK to drive the convolution encoder, CE_OUT can be captured on the falling edge of CLK_OUT.
DC CHARACTERISTICS AND RATINGS
Parameter Supply Voltage Input Voltage Current Through Any Pin Operating Temperature Storage Temperature Min -0.5 -0.3 -20 -55 -65 Max 7 VDD+0.3 +20 125 150 Units V V mA C C Note: Stresses above those listed may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these conditions, or at any other condition above those indicated in the operations section of this specification, is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Table 3: Absolute Maximum Ratings
Symbol VDD VIH VIL VOH VOL IIL IPDL IDD1 IDD2
Parameter Supply Voltage CMOS Input High Voltage CMOS Input Low Voltage CMOS Output High Voltage CMOS Output Low Voltage Input Leakage Current Input Pull-Down Current Static Power Supply Current Dynamic Power Supply Current
Conditions VDD = 5.5V VDD = 5.5V VDD = 5V, IOH = -1.0mA VDD = 5V, IOL = 4.0mA VDD = 5.5V, VIN = VSS or VDD VDD = 5.5V, VIN = VSS or VDD VDD = 5.5V CLK = 10MHz, VDD = 5.5V
Min 4.5 0.8 VDD VSS VDD-0.5 -10 -20 -
Typ 5.0 0.1 3
Max 5.5 VDD 0.2 VDD 0.4 10 150 2.5 10
Units V V V V V A A mA mA
Notes: 1. VDD = 5V10%, over full operating temperature range. 2. Total dose radiation not exceeding 1x105 Rads(Si) 3. Mil-Std-883, method 5005, subgroups 1, 2, 3 Table 4: DC Electrical Characteristics
AC CHARACTERISTICS
No. 1 2 3 4 5 6 7 8 9 10 11 12 13 Parameter CLK hlgh to CLKS CLK high to SYZ or SZY SMC hold after CLK low SMC setup to CLK low MSG set up to CLKS high MSG hold after CLKS high MSG to RSE_OUT propagation delay CLKS to RSE_OUT (SMC low) CLK to CLK_OUT propagation delay CE_IN setup to CE_CLK hlgh CE_IN hold after CE_CLK high CE_CLK to CE_OUT CLK CYCLE TIME Min. 0 30 10 10 10 10 100 Max. 25 30 30 25 25 25 Units ns ns ns ns ns ns ns ns ns ns ns ns ns
Note: Mil-Std-883, method 5005, subgroups 9, 10, 11
Table 5: AC Electrical Characteristics
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MA1916
Symbol CIN COUT Parameter Input Capacitance Output Capacitance Conditions Vl = 0V VI/O = 0V Min. Typ. 3 5 Max. 5 7 Units pF pF
Note: TA = 25C and f = 1MHz. Data obtained by characterisation or analysis; not routinely measured. Table 6: Capacitance
Symbol FT
Parameter Functionality
Conditions VDD = 4.5V - 5.5V, Frequency = 1MHz VIL = VSS, VIH = VDD, VOL = VOH = VDD/2 Temperature = -55C to +125C, Radiation to 1MRad Total Dose Mil-Std-883, method 5005, subgroups 7, 8A, 8B Table 7: Functionality
Subgroup 1 2 3 7 8A 8B 9 10 11
Definition Static characteristics specified in Table 4 at +25C Static characteristics specified in Table 4 at +125C Static characteristics specified in Table 4 at -55C Functional characteristics specified in Table 7 at +25C Functional characteristics specified in Table 7 at +125C Functional characteristics specified in Table 7 at -55C Switching characteristics specified in Table 5 at +25C Switching characteristics specified in Table 5 at +125C Switching characteristics specified in Table 5 at -55C Table 8: Definition of Subgroups
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MA1916
TIMING DIAGRAMS
*
Note: Bytes of MSG labelled 0 to 222 x I Bytes of RSE_OUT labelled 0 to 254 x I Bits labelled 0 to 7 I = Interleave depth of 1, 4 or 5 * User can capture RSE_OUT on rising edge of CLKS Figure 6: RS Encoder Timings
See Note 2
Notes: 1. If CE_CLK is driven by CLKS, the user can capture CE_OUT on the falling edge of CLK_OUT. 2. Arrows show which O/P bits correspond to which I/P bit.
Figure 7: Convolution Encoder Timings
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MA1916
OUTLINES AND PIN ASSIGNMENTS
Millimetres Min. 0.38 0.35 0.20 4.71 Nom. 2.54 Typ. 15.24 Typ. Max. 5.715 1.53 0.59 0.36 36.02 5.38 15.90 1.27 1.53 Min. 0.015 0.014 0.008 0.185 Inches Nom. 0.100 Typ. 0.600 Typ. Max. 0.225 0.060 0.023 0.014 1.418 0.212 0.626 0.050 0.060
Ref A A1 b c D e e1 H Me Z W
XG404
D
TOP VIEW
14
1
15
28
W Seating Plane ME
A1 A
H e b Z 15
C e1
Figure 8: 28-Lead Ceramic DIL (Solder Seal) - Package Style C
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MA1916
Ref A Q b c D e L M
Millimetres Min. 0.66 0.38 0.10 18.08 7.62 12.50 Nom. 1.27 Max. 3.18 0.48 0.18 18.49 9.91 12.09 Min. 0.026 0.015 0.004 0.712 0.300 0.492
Inches Nom. 0.050 Max. 0.125 0.019 0.007 0.728 0.390 0.508
XG530
M b
D
Z
e L A c
ME Q
Pin 1
Figure 9: 28-Lead Ceramic Flatpack (Solder Seal) - Package Style F
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MA1916
MSG_OUT 28 CLK_OUT 27 SMC 26 RSE_OUT 25 SYZ 24 T3 23 CLKS 22 VDD 21 N/C 20 T0 19 MSG 18 CLK 17 READY 16 SMC_OUT 15 Bottom View
1 T2 2 T1 3 CE_CLKS 4 CE_IN 5 CE_OUT 6 TEST_POINT 7 N/C 8 ST1 9 GND 10 SEL_A 11 STZ 12 SEL_B 13 SZY 14 n_RST
Figure 10: Flatpack Pinout
RADIATION TOLERANCE
Total Dose Radiation Testing For product procured to guaranteed total dose radiation levels, each wafer lot will be approved when all sample devices from each lot pass the total dose radiation test. The sample devices will be subjected to the total dose radiation level (Cobalt-60 Source), defined by the ordering code, and must continue to meet the electrical parameters specified in the data sheet. Electrical tests, pre and post irradiation, will be read and recorded. Dynex Semiconductor can provide radiation testing compliant with Mil-Std-883 test method 1019, Ionizing Radiation (Total Dose).
Total Dose (Function to specification)* Transient Upset (Stored data loss) Transient Upset (Survivability) Neutron Hardness (Function to specification) Single Event Upset** Latch Up
1x105 Rad(Si) 5x1010 Rad(Si)/sec >1x1012 Rad(Si)/sec >1x1015 n/cm2 <1x10-10 Errors/bit day Not possible
* Other total dose radiation levels available on request ** Worst case galactic cosmic ray upset - interplanetary/high altitude orbit Table 9: Radiation Hardness Parameters
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ORDERING INFORMATION
Unique Circuit Designator
Radiation Tolerance S R Q H Radiation Hard Processing 100 kRads (Si) Guaranteed 300 kRads (Si) Guaranteed 1000 kRads (Si) Guaranteed
MAx1916xxxxx
QA/QCI Process (See Section 9 Part 4)
Test Process (See Section 9 Part 3) Package Type C F L Ceramic DIL (Solder Seal) Flatpack (Solder Seal) Leadless Chip Carrier Assembly Process (See Section 9 Part 2)
Reliability Level L C D E B S Rel 0 Rel 1 Rel 2 Rel 3/4/5/STACK Class B Class S
For details of reliability, QA/QC, test and assembly options, see `Manufacturing Capability and Quality Assurance Standards' Section 9.
http://www.dynexsemi.com e-mail: power_solutions@dynexsemi.com
HEADQUARTERS OPERATIONS DYNEX SEMICONDUCTOR LTD Doddington Road, Lincoln. Lincolnshire. LN6 3LF. United Kingdom. Tel: 00-44-(0)1522-500500 Fax: 00-44-(0)1522-500550 DYNEX POWER INC. Unit 7 - 58 Antares Drive, Nepean, Ontario, Canada K2E 7W6. Tel: 613.723.7035 Fax: 613.723.1518 Toll Free: 1.888.33.DYNEX (39639) CUSTOMER SERVICE CENTRES France, Benelux, Italy and Spain Tel: +33 (0)1 69 18 90 00. Fax: +33 (0)1 64 46 54 50 North America Tel: 011-800-5554-5554. Fax: 011-800-5444-5444 UK, Germany, Scandinavia & Rest Of World Tel: +44 (0)1522 500500. Fax: +44 (0)1522 500020 SALES OFFICES France, Benelux, Italy and Spain Tel: +33 (0)1 69 18 90 00. Fax: +33 (0)1 64 46 54 50 Germany Tel: 07351 827723 North America Tel: (613) 723-7035. Fax: (613) 723-1518. Toll Free: 1.888.33.DYNEX (39639) / Tel: (831) 440-1988. Fax: (831) 440-1989 / Tel: (949) 733-3005. Fax: (949) 733-2986. UK, Germany, Scandinavia & Rest Of World Tel: +44 (0)1522 500500. Fax: +44 (0)1522 500020 These offices are supported by Representatives and Distributors in many countries world-wide. (c) Dynex Semiconductor 2000 Publication No. DS3590-5 Issue No. 5.0 January 2000 TECHNICAL DOCUMENTATION - NOT FOR RESALE. PRINTED IN UNITED KINGDOM
Datasheet Annotations: Dynex Semiconductor annotate datasheets in the top right hard corner of the front page, to indicate product status. The annotations are as follows:Target Information: This is the most tentative form of information and represents a very preliminary specification. No actual design work on the product has been started. Preliminary Information: The product is in design and development. The datasheet represents the product as it is understood but details may change. Advance Information: The product design is complete and final characterisation for volume production is well in hand. No Annotation: The product parameters are fixed and the product is available to datasheet specification.
This publication is issued to provide information only which (unless agreed by the Company in writing) may not be used, applied or reproduced for any purpose nor form part of any order or contract nor to be regarded as a representation relating to the products or services concerned. No warranty or guarantee express or implied is made regarding the capability, performance or suitability of any product or service. The Company reserves the right to alter without prior notice the specification, design or price of any product or service. Information concerning possible methods of use is provided as a guide only and does not constitute any guarantee that such methods of use will be satisfactory in a specific piece of equipment. It is the user's responsibility to fully determine the performance and suitability of any equipment using such information and to ensure that any publication or data used is up to date and has not been superseded. These products are not suitable for use in any medical products whose failure to perform may result in significant injury or death to the user. All products and materials are sold and services provided subject to the Company's conditions of sale, which are available on request. All brand names and product names used in this publication are trademarks, registered trademarks or trade names of their respective owners.
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