STMicroelectronics L4998 Datasheet
Contents
1. wa AN2357 Y7 Application note Connecting ST10F252 evaluation board to the airbag eva board Introduction The aim of this document is to provide the necessary information to implement the modifications to connect the ST airbag eva board MB467 to the ST10F252 evaluation board MB449 A very brief application overview is followed by an explanation on how to manage the signals involved Finally hints on how to supply the entire system are provided June 2006 Rev 1 1 12 www st com Contents AN2357 Contents 1 Application overview 0 00 c cee ees 3 1 1 MB449 oard rr 4 1 2 MB467 board cosas see bee eh HE Re eS atuk EEI EnEn SA EES oe Shee ee 5 2 Interconnection organization ST10F252 point of view 6 2 1 Reset signal scetur oA ecu EUR RR NR ERAS ES Sac Prat 6 22 SPI SSC and CS signals ies RAE REX ie bevcennewas 6 23 JAnalog pls 2222262224024 RAS eR da ge tions E AY Qe aud 7 2 4 Satellite inputs simulation llle 7 2 5 Message waiting signals management 0 e ee eee eee 7 2 6 Deployment enable signals 0 000 c ee ee 8 3 How to supply the boards 00 cee eee eee 10 4 Revision history uadcacus etree aden cere eed ed ee wee news 11 2 12 Ti AN2357 Application overview Application overview An airbag safety system interprets decelerations monitored by satellite sensors identifies crash situations and actuates the squibs to inflate the2. 4 B9 therefore e B9 lt gt D17 Deployment enable signals DEPEN Deployment Enable is the last signal used to start the deployment L9654 DEPEN has been designed to be connected to ST10F252 P4 0 used as GPIO whereas L9658 DEPEN is linked to P3 1 used as GPIO as well No extra connection is needed Table 1 Connection table extemal Pin Name Description connection none A12 RESETB Reset A7 A16 MOSI Satellite Deployment Data in A2 A18 DICH3 Channel 3 Satellite Sensor input simulation for L9658 none A22 DEPEN Deployment enable input for L9654 none A23 DICH5 Channel 1 Satellite input simulation for L9654 A8 A25 CS S1 Chip select for Satellite Interface of L9658 Current Feedback for channel 3 raw or data output for channel 3 of the none A26 IF3 L9658 none A27 AOUT Analog output for loop diagnostic for L9658 B7 B15 SCLK Satellite Deployment SPI Clock B6 B16 MISO _ Satellite Deployment SPI Data Output B2 B18 DICH4 Channel 4 Satellite Sensor input simulation for L9658 none B23 DICH6 Channel 2 Satellite input simulation for L9654 B8 B25 CS D1 Chip select for Deployment Driver of L9658 Current Feedback for channel 4 raw or data output for channel 4 of the none B26 IFA 9658 none B27 AOUT2 Analog output for loop diagnostic for L9654 none C19 DICH1 Channel 1 Satellite input simulation for L9658 none C26 MOSI_A Arm
3. IR CRAFT SPACE LIFE SAVING OR LIFE SUSTAINING APPLICATIONS NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY DEATH OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE Resale of ST products with provisions different from the statements and or technical features set forth in this document shall immediately void any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever any liability of ST ST and the ST logo are trademarks or registered trademarks of ST in various countries Information in this document supersedes and replaces all information previously supplied The ST logo is a registered trademark of STMicroelectronics All other names are the property of their respective owners 2006 STMicroelectronics All rights reserved STMicroelectronics group of companies Australia Belgium Brazil Canada China Czech Republic Finland France Germany Hong Kong India Israel Italy Japan Malaysia Malta Morocco Singapore Spain Sweden Switzerland United Kingdom United States of America www st com 12 12 ky
4. balloons see Figure 1 Figure 1 Airbag system Inflator Squib Airbag Sensor Assembly Power Safing Source Sensor Bag PSY gt gt inflator For Driver YR Airbag Sensor ans Collision Impact E Front Airbag Sensors LH RH Bag For Front Passenger To Seat Belt Pretensioner From a technical point of view a typical airbag system comprises no less than a microcontroller a squib driver satellite sensor interface satellites sensors squibs a safety power regulator STMicroelectronics offers a complete solution for the development of airbag systems from microcontrollers to squib and satellite drivers to power regulators see Figure 2 Airbag system block diagram on page 4 3 12 Application overview AN2357 1 1 4 12 Figure 2 Airbag system block diagram Buck fault Vbatt 12V Vcc fault ST L4998 power regulator Vcc Vcc Vbuck Vboost 5V 5V 8V 35V EE ees se ees Squib driver sez A Satellite ST Microcontroller Sensor I ST10 ST30 eios Dep En interface p SQUIBn Msg W j 1 Satellite inputs simulation MB449 board The MB449 ST10F25x Eva board is a standalone evaluation board for the ST10F252 and ST10F251 devices Main components socket for ST10F25x microcontroller TQFP100 256Kx16 bit High Speed Static RAM L9616 CAN transce
5. essary e A7 lt gt A16 e B6 lt gt B16 e B7 lt gt B15 No ST10F252 pin is linked to A16 B16 or B15 of the standard connector Moreover two CS signals are used to address the satellite sensor and deployment interface per each device total of four Some pins have been identified Pin 3 6 D27 as CS_S2 AN2357 Interconnection organization ST10F252 point of view 2 3 2 4 2 5 L9654 does not need any other connection The other pins chosen have no direct connection with ST10F252 therefore three output pins must be designed for instance CS_S1 L9658 can be connected to P1H 4 A8 CS D1 L9658 can be connected to P1H 5 B8 CS D2 L9654 can be connected to P1H 6 A9 In this case the following external connections are required e A8 lt gt A25 e B8 lt gt B25 e A9 lt gt C29 Remember to free up port P1 from the address generation using only multiplexed modes external RAM present on the ST10F25x evaluation board cannot be used Analog inputs The L9658 provides two analog outputs IF3 IF4 reporting signals coming from Hall sensors plus an analog output AOUT for loop diagnostics The L9654 provides only an analog output AOUT signal Analog inputs port P5 0 port P5 1 port P5 2 and port P5 3 have been chosen No other connections are needed Satellite inputs simulation Satellite inputs to L965x can be emulated by the microcontroller for testing purposes The L9658 s
6. ing SPI Data In none C27 CS A2 Chip select for Arming Interface of L9654 A9 C29 CS D2 Chip select for Deployment Driver of L9654 none C30 DEPEN1 Deployment enable input for L9658 B9 D17 MSG2 Message waiting for L9654 AN2357 Interconnection organization ST10F252 point of view Table 1 Connection table continued sei UR Pin Name Description none D18 BCKFLT Buck fault output none D19 DICH2 Channel 2 Satellite input simulation for L9658 none D25 SCLK A Arming SPI Clock none D26 MISO A Arming SPI Data Out none D27 CS S2 Chip select for Satellite Interface of L9654 none D29 MSG Message waiting for L9658 none D30 CS A1 Chip select for Arming Interface of L9658 9 2 How to supply the boards AN2357 3 How to supply the boards Once coupled both the boards can be supplied through only one power supply 12V applied to the airbag eva board airbag eva board jumpers J48 J50 closed 10 12 r AN2357 Revision history 4 Revision history Table 2 Document revision history Date Revision Changes 26 Jun 2006 1 Initial release 11 12 AN2357 Please Read Carefully Information in this document is provided solely in connection with ST products STMicroelectronics NV and its subsidiaries ST reserve the right to make changes corrections modifications or improvements
7. iver ST232ABDR RS232 transceiver standardized CPU board connector providing access to off board I O PWM SSC and power supply Features e Supportfor the following interfaces CAN A RS232 serial port User buttons and LEDs e Main power supply 5V AN2357 Application overview Please refer to the MB449 User Manual UM0186 for more details about the board and to the ST10F25x User Manual for more details about the microcontroller functionalities 1 2 MB467 board The MB467 Airbag Eva board is a complete demonstrator of an airbag system based on STMicroelectronics devices The board implements a flexible and open design demonstrating the capability of the STMicroelectronics 16 32 bit microcontrollers and safing devices for airbag applications The MB467 Airbag Eva board mounts two safing devices with squib drivers and satellite sensor interfaces L9654 and L9658 plus a safety power regulator L4998 The board has open connectivity to ST CPU boards squibs and to the external power supply A prototyping area allows users to extend the board s functionality with specific circuitry Main components L9658 octal squib driver and quad sensor interface ASIC for safety application e L9654 quad squib driver and dual sensor interface ASIC for safety application e L4998 safety power regulator e standardized CPU board connector providing access to off board I O PWM SPI and power supply e connector for squibs co
8. nnector for satellites e connector for Hall sensors Features e Supports the ST30F7xx and ST10Fxxx Eva boards e Support for up to 6 satellites or 4 satellites and 2 Hall sensors real or simulated e Support for up to 12 squibs real or simulated e Diagnostic testing and validation of safing functionality SPI arming and deployment squibs and deployment drivers loss of ground and short circuit satellites communication e Onboard standard 100 mils prototyping area e Main power supply 12V Please refer to the board MB467 User Manual UMO178 for more details 5 2 Interconnection organization ST10F252 point of view AN2357 2 2 1 2 2 6 12 Interconnection organization ST10F252 point of view ST10F25x is a derivative of the STMicroelectronics ST10 family of 16 bit single chip CMOS microcontrollers Unlike the other members of the family ST10F25x is a 100 pin package Due to this pin count limitation some pin alternate functionalities have been either remapped on other pins or completely removed The airbag evaluation board has been designed to be coupled directly with the ST30F7xx boards however with some minor modifications this board can be adapted for use with ST10F25x board In the remainder of the chapter all the signals involved will be examined in order to underline the differences and to provide the necessary modifications Figure 2 Airbag system block diagram on page 4 summarizes all the connections req
9. to this document and the products and services described herein at any time without notice All ST products are sold pursuant to ST s terms and conditions of sale Purchasers are solely responsible for the choice selection and use of the ST products and services described herein and ST assumes no liability whatsoever relating to the choice selection or use of the ST products and services described herein No license express or implied by estoppel or otherwise to any intellectual property rights is granted under this document If any part of this document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products or services or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such third party products or services or any intellectual property contained therein UNLESS OTHERWISE SET FORTH IN ST S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY WITH RESPECT TO THE USE AND OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED WARRANTIES OF MERCHANTABILITY FITNESS FOR A PARTICULAR PURPOSE AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION OR INFRINGEMENT OF ANY PATENT COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZE REPRESENTATIVE OF ST ST PRODUCTS ARE NOT DESIGNED AUTHORIZED OR WARRANTED FOR USE IN MILITARY A
10. uired Reset signal The microcontroller reset signal RSTIN pin A12 in the connector is driven by the L4998 Safety Power Regulator SPR no other connection is necessary The SPR also provides an indication of the buck voltage BCKFLT This signal has been directed to an ST10F252 GPIO Pin P2 3 pin D18 on the connector which can also be used as a CAPTURE input No other connection is needed SPI SSC and CS signals The ST10F25x and L965x communicate through two SPI interfaces The first is dedicated to the deployment and the satellite communication S D in Figure 2 on page 4 and the other is used for the arming A in Figure 2 In addition three chip select signals per device total of six are necessary to address each interface separately satellite sensor deployment and arming The arming interface has been mapped on the standard ST10F252 SSC interface MTSRO pin P3 9 MRSTO pin P3 8 SCLKO pin P3 13 C26 D26 D25 respectively in the connector Pin P3 0 and pin 3 7 D30 and C27 in connector have been designed to be used as CS for L9658 and L9654 respectively No extra connection needed The satellite sensor deployment interface has been mapped on the other SSC interface ST10F252 XSSC In the ST10F252 XBUS peripherals use port P1 In detail MTSR1 is mapped on P1H 2 A7 MRST1 pin P1H 1 B6 and SCLK1 pin P1H 3 B7 For this reason an external connection using dedicated wires between these pins of the connector are nec
11. upports up to four satellites whereas L9654 supports up to two satellites For this reason up to six ST10F252 outputs must be dedicated to the satellite inputs simulation either PWMs or GPIOs DICH1 and DICH2 L9658 are linked to port P2 4 and port P2 5 respectively GPIOs or COMPARE outputs DICH5 and DICH6 are linked to port P4 2 and port P4 3 respectively PWMs Remember to set SW4 2 OFF and SW4 3 ON to disable segment address lines There is no direct correspondence for the remaining signals DICH3 and DICH4 These two signals should be linked to other PWM outputs for instance DICH3 can be connected to XPWMO P1L 0 A2 DICH4 can be connected to XPWM1 P1L 1 B2 In this case the following external connections are required e A2 lt gt A18 e B2 lt gt B18 Message waiting signals management There is another very important signal coming from L965x Message Waiting MSG MSG can be configured active HIGH or active LOW MSG is used only to notify that a satellite message is present in the satellite FIFO The MSG signal related to L9658 is linked to port 7 12 Interconnection organization ST10F252 point of view AN2357 2 6 8 12 P3 2 This pin is used as CAPIN capture input in the ST10 microcontroller an interrupt is also linked to this event Since the MSG signal related to L9654 has no direct correspondence an external connection is needed An ST10F252 capture input can be used for instance P1H
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