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1. general description the UJA1164 is a mini high-speed can sy stem basis chip (sbc) containing an iso 11898-2/5 compliant hs-can transceiver and an integrated 5 v/100 ma supply for a microcontroller. it also features a watchdog and a serial peripheral interface (spi). the UJA1164 can be operated in a very low-current standby mode with bus wake-up capability and supports iso 11898-6 compliant autonomous can biasing. a number of configuration sett ings are stored in non-volatile memory, allowing the sbc to be adapted for use in a specific application. this makes it possib le to configure the power-on behavior of the UJA1164 to meet the requirements of different applications. 2. features and benefits 2.1 general ? iso 11898-2 and iso 11898-5 compliant high-speed can transceiver ? autonomous bus biasing according to iso 11898-6 ? fully integrated 5 v/100 ma low-drop voltage regulator for 5 v microcontroller supply (v1) ? bus connections are truly floating when power to pin bat is off 2.2 designed for automotive applications ? ? 8 kv electrostatic discharge (esd) protection, according to the human body model (hbm) on the can bus pins ? ? 6 kv esd protection, according to iec 61000-4-2 on the can bus pins and on pin bat ? can bus pins short-circuit proof to ? 58 v ? battery and can bus pins protected against automotive transients according to iso 7637-3 ? very low quiescent curr ent in standby mode wit h full wake-up capability ? leadless hvson14 package (3.0 mm ? 4.5 mm) with improved automated optical inspection (aoi) capability and low thermal resistance ? dark green product (halogen free and rest riction of hazardous substances (rohs) compliant) 2.3 low-drop voltage regulator for 5 v microcontroller supply (v1) ? 5 v nominal output; ? 2 % accuracy ? 100 ma output cu rrent capability UJA1164 mini high-speed can system ba sis chip with standby mode & watchdog rev. 1 ? 5 august 2013 product data sheet
UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 2 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog ? current limiting above 150 ma ? on-resistance of 5 ? (max) ? support for microcontroller ram retention down to a battery voltage of 2 v ? undervoltage reset with selectable detection thresholds: 60 %, 70 %, 80 % or 90 % of output voltage ? excellent transient response with a 4.7 ? f ceramic output capacitor ? short-circuit to gnd/overload protection on pin v1 2.4 power management ? standby mode featuring very low supply current; voltage v1 remains active to maintain the supply to the microcontroller ? remote wake-up capability via standard can wake-up pattern ? wake-up source recognition ? remote wake-up can be disabled to reduce current consumption 2.5 system control and diagnostic features ? mode control via the serial peripheral interface (spi) ? overtemperature warning and shutdown ? watchdog with independent clock source ? watchdog can be operated in window, timeout and autonomous modes ? optional cyclic wake-up in watchdog timeout mode ? watchdog automatically re-enabled when wake-up event captured ? watchdog period selectable between 8 ms and 4 s ? supports remote flash programming via the can bus ? 16-, 24- and 32-bit spi for conf iguration, control and diagnosis ? bidirectional reset pin with variable power- on reset length to support a variety of microcontrollers ? configuration of selected functions via non-volatile memory 3. ordering information table 1. ordering information type number package name description version UJA1164tk hvson14 plastic thermal enhanced very thin small outline package; no leads; 14 terminals; body 3 ? 4.5 ? 0.85 mm sot1086-2 UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 3 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog 4. block diagram fig 1. block diagram of UJA1164 UJA1164 5 v microcontroller supply (v1) rstn v1 watchdog hs-can canh canl txd rxd sdi sck scsn sdo spi 015aaa268 5 3 13 12 bat 10 4 1 8 11 6 14 gnd 2 UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 4 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog 5. pinning information 5.1 pinning 5.2 pin description [1] hvson14 package die supply grou nd is connected to both the gnd pi n and the exposed center pad. the gnd pin must be soldered to board ground. for enhanc ed thermal and electrical performance, it is recommended to also solder the exposed center pad to board ground. fig 2. pin configuration diagram terminal 1 index area 015aaa441 UJA1164 txd 1 gnd 2 3 rxd 4 5 sdo 6 i.c. scsn canh canl sdi bat i.c. sck 7 14 13 12 11 10 9 8 transparent top view v1 rstn table 2. pin description symbol pin description txd 1 transmit data input gnd 2 [1] ground v1 3 5 v microcontroller supply voltage rxd 4 receive data output; reads out data from the bus lines rstn 5 reset input/output sdo 6 spi data output i.c. 7 internally connected; should be left floating or connected to gnd sck 8 spi clock input i.c. 9 internally connected; should be left floating or connected to gnd bat 10 battery supply voltage sdi 11 spi data input canl 12 low-level can bus line canh 13 high-level can bus line scsn 14 spi chip select input UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 5 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog 6. functional description 6.1 system controller the system controller manages register confi guration and controls the internal functions of the UJA1164. detailed device status information is collected and made available to the microcontroller. 6.1.1 operating modes the system controller contains a state machine that supports six operating modes: normal, standby, reset, forced normal, overtemp and off. the state transitions are illustrated in figure 3 . 6.1.1.1 normal mode normal mode is the active operating mode. in this mode, all the hardware on the device is available and can be activated (see ta b l e 3 ). voltage regulator v1 is enabled to supply the microcontroller. the can interface can be configured to be active and thus to support normal can communication. depending on the spi register settings, the watchdog may be running in window or timeout mode. normal mode can be selected from standby mode via an spi command (mc = 111). 6.1.1.2 standby mode standby mode is the UJA1164?s power saving mode, offering reduced current consumption. the transceiver is unable to transmit or receive data in standby mode. the spi remains enabled and v1 is still active; the watchdog is active (in timeout mode) if enabled. if remote can wake-up is enabled (cwe = 1; see ta b l e 2 4 ), the receiver monitors bus activity for a wake-up request. the bus pins are biased to gnd (via r i(cm) ) when the bus is inactive for t > t to(silence) and at approximately 2.5 v when there is activity on the bus (autonomous biasing). pin rxd is forced low when any enabled wake-up event is detected. this can be either a regular wake-up (via the can bus) or a diagnostic wake-up such as an overtemperature event (see section 6.8 ). the UJA1164 switches to standby mode via reset mode: ? from off mode if the battery voltage rise s above the power-on detection threshold (v th(det)pon ) ? from overtemp mode if the chip temperature falls below the overtemperature protection release threshold, t th(rel)otp standby mode can also be selected from normal mode via an spi command (mc = 100). UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 6 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog 6.1.1.3 reset mode reset mode is the reset execution state of the sbc. this mode ensures that pin rstn is pulled down for a defined time to allow the microcontroller to start up in a controlled manner. the transceiver is unable to transmit or rece ive data in reset mode. the spi is inactive; the watchdog is disabled; v1 and ov ertemperature detection are active. the UJA1164 switches to reset mode from any mode in response to a reset event (see ta b l e 5 for a list of reset sources). the UJA1164 exits reset mode: ? and switches to standby mode if pin rstn is released high ? and switches to forced normal mode if bit fnmc = 1 ? if the sbc is forced into off or overtemp mode if a v1 undervoltage event forced the transit ion to reset mo de, the UJA1164 will remain in reset mode until the voltage on pin v1 has recovered. fig 3. UJA1164 system controller state diagram standby mc = normal 015aaa271 mc = standby normal no overtemperature overtemp rstn = high overtemperature event from any mode except off reset power-on off from any mode v bat undervoltage v1 undervoltage any reset event forced normal from reset mode if fnmc = 1 any reset event mtp programming completed or mtp factory presets restored UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 7 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog 6.1.1.4 off mode the UJA1164 switches to off mode when the ba ttery is first connected or from any mode when v bat < v th(det)poff . only power-on detection is enabled; all other modules are inactive. the UJA1164 starts to boot up when the battery voltage rises above the power-on detection threshold v th(det)pon (triggering an initializat ion process) and switches to reset mode after t startup . in off mode, the can pins disengage from the bus (zero load; high-ohmic). 6.1.1.5 overtemp mode overtemp mode is provided to prevent the UJA1164 being damaged by excessive temperatures. the UJA1164 switches immedi ately to overtemp mode from any mode (other than off mode) when the global chip temperature rises above the overtemperature protection activation threshold, t th(act)otp . to help prevent the loss of data due to over heating, the UJA1164 issues a warning when the ic temperature rises above the overtemperature warning threshold (t th(warn)otp ). when this happens, status bit otws is set and an overtemperature warning event is captured (otw = 1), if enabled (otwe = 1). in overtemp mode, the can transmitter and receiver are disabled and the can pins are in a high-ohmic state. no wake-up event will be detected, but a pending wake-up will still be signalled by a low level on pin rxd, which will persist after the overtemperature event has been cleared. v1 is off and pin rstn is driven low. the UJA1164 exits overtemp mode: ? and switches to reset mode if the chip temperature falls below the overtemperature protection release threshold, t th(rel)otp ? if the device is forced to switch to off mode (v bat < v th(det)poff ) 6.1.1.6 forced normal mode forced normal mode simplifies sbc testing and is useful for initial prototyping and failure detection, as well as first flashing of the mi crocontroller. the watchdog is disabled in forced normal mode. the low-drop voltage regulator (v1) and the can transceiver are active. bit fnmc is factory preset to 1, so the uja1 164 initially boots up in forced normal mode (see table 8 ). this allows a newly installed device to be run in normal mode without a watchdog. so the microcontroller can be flas hed via the can bus in the knowledge that a watchdog timer overflow will not trigger a system reset. the register containing bit fnmc (address 74 h) is stored in non-volatile memory (see section 6.9 ). so once bit fnmc is programmed to 0, the sbc will no longer boot up in forced normal mode, allowing the watchdog to be enabled. even in forced normal mode, a reset event (e.g. an external reset or a v1 undervoltage) will trigger a transition to reset mode with normal reset mode b ehavior (e.g. can goes offline). however, when the UJA1164 exits re set mode, it will return to forced normal mode instead of switching to standby mode. in forced normal mode, only the main status register, the watchdog status register, the identification register and registers stored in non-volatile memory can be read. the non-volatile memory area is fu lly accessible for writing as long as the UJA1164 is in the UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 8 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog factory preset state (for details see section 6.9 ). the UJA1164 switches from reset mode to forced normal mode if bit fnmc = 1. 6.1.1.7 hardware characterization for the UJA1164 operating modes [1] when the sbc switches from reset, standby or normal mode to of f mode, v1 behaves as a current source during power down while v bat is between 3 v and 2 v. [2] window mode is only active in normal mode. 6.1.2 system control registers the operating mode is selected via bits mc in the mode control register. the mode control register is accessed via spi address 0x01 (see section 6.13 ). the main status register can be accessed to monitor the status of the overtemperature warning flag and to determine whether the uj a1164 has entered normal mode after initial power-up. it also indicates the source of the most recent reset event. table 3. hardware characterization by functional block block operating mode off forced normal standby normal reset overtemp v1 off [1] on on on on off rstn low high high high low low spi disabled active active active disabled disabled watchdog off off determined by bits wmc (see ta b l e 7 ) [2] determined by bits wmc [2] off off can floating active offline active/ offline/ listen-only (determined by bits cmc; see table 14 ) offline floating rxd v1 level can bit stream v1 level/low if wake-up detected can bit stream if cmc = 01/10/11; otherwise same as standby v1 level/low if wake-up detected v1 level/low if wake-up detected table 4. mode control register (address 01h) bit symbol access value description 7:3 reserved r - 2:0 mc r/w mode control: 100 standby mode 111 normal mode table 5. main status register (address 03h) bit symbol access value description 7 reserved r - 6 otws r overtemperature warning status: 0 ic temperature below overtemperature warning threshold 1 ic temperature above overtemperature warning threshold UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 9 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog 6.2 watchdog the UJA1164 contains a watchdog that supports three operating modes: window, timeout and autonomous. in window mode (available only in sbc normal mode), a watchdog trigger event within a closed watchdog window resets the watchdog timer. in timeout mode, the watchdog runs continuously and can be reset at any time within the timeout time by a watchdog trigger. watchdog timeout mode can also be used for cyclic wake-up of the microcontroller. in autonomous mode, the watchdog can be off or in timeout mode (see section 6.2.4 ). the watchdog mode is selected via bits wmc in the watchdog control register ( ta b l e 7 ). the sbc must be in standby mode when the watchdog mode is changed. if window mode is selected (wmc = 100), the watchdog will remain in (or switch to) timeout mode until the sbc enters normal mode. any atte mpt to change the watchdog operating mode (via wmc) while the sbc is in normal mode will cause the UJA1164 to switch to reset mode and the reset source status bits (r ss) will be set to 1000 0 (?illegal watchdog mode control access?; see ta b l e 5 ). eight watchdog periods are supported, from 8 ms to 4096 ms. the watchdog period is programmed via bits nwp. the selected period is valid for both window and timeout modes. the default watchdog period is 128 ms. a watchdog trigger event resets the watchdog timer. a watchdog trigger event is any valid write access to the watchdog control register. if the watchdog mode or the watchdog period have changed as a result of the write access, the new values are immediately valid. 5 nms r normal mode status: 0 UJA1164 has entered normal mode (after power-up) 1 UJA1164 has powered up but has not yet switched to normal mode 4:0 rss r reset source status: 00000 exited off mode (power-on) 01110 watchdog triggered too early (window mode) 01111 watchdog overflow (window mode or timeout mode with wdf = 1) 10000 illegal watchdog mode control access 10001 rstn pulled down externally 10010 exited overtemp mode 10011 v1 undervoltage table 5. main status register (address 03h) ?continued bit symbol access value description UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 10 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog [1] default value if sdmc = 1 (see section 6.2.1 ) [2] default value. [3] selected in standby mode but only activated when the sbc switches to normal mode. the watchdog is a valuable safety mechanism, so it is critical th at it is configured correctly. two features are provided to prevent watchdog parameters being changed by mistake: ? redundant states of configuration bits wmc and nwp ? reconfiguration protection in normal mode redundant states associated with control bits wmc and nwp ensure that a single bit error cannot cause the watchdog to be configur ed incorrectly (at least two bits must be changed to reconfigure wmc or nwp). if an atte mpt is made to write an invalid code to wmc or nwp (e.g. 011 or 1001 respectively), the spi operation is abandoned and an spi failure event is captured, if enabled (see section 6.8 ). two operating modes have a major impact on the operation of the watchdog: forced normal mode and software development mode (software development mode is provided for test purposes and is not an sbc operating mode; the UJA1164 can be in any mode with software development mode enabled; see section 6.2.1 ). these modes are enabled and disabled via bits fnmc and sdmc resp ectively in the sbc configuration control table 6. summary of watchdog settings watchdog configuration via spi fnmc000 0 1 sdmcxx0 1 x wmc 100 (window) 010 (timeout) 001 (autonomous) 001 (autonomous) n.a. sbc operating mode normal mode window timeout timeout off off standby mode (rxd high) timeout timeout off off off standby mode (rxd low) timeout timeout timeout off off other modes off off off off off table 7. watchdog control register (address 00h) bit symbol access value description 7:5 wmc r/w watchdog mode control: 001 [1] autonomous mode 010 [2] timeout mode 100 [3] window mode 4 reserved r - 3:0 nwp r/w nominal watchdog period 1000 8 ms 0001 16 ms 0010 32 ms 1011 64 ms 0100 [2] 128 ms 1101 256 ms 1110 1024 ms 0111 4096 ms UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 11 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog register (see ta b l e 8 ). note that this register is loca ted in the non-volatile memory area (see section 6.8 ). in forced normal mode (fnm), th e watchdog is completely disabled. in software development mode (sdm), the watch dog can be disabled or activated for test purposes. information on the status of th e watchdog is available from the watchdog status register ( ta b l e 9 ). this register also indicates whether forced normal and so ftware development modes are active. [1] factory preset value. table 8. sbc configuration control register (address 74h) bit symbol access value description 7:6 reserved r - 5:4 v1rtsuc r/w v1 reset threshold (defined by bit v1rtc) at start-up: 00 [1] v1 undervoltage detection at 90 % of nominal value at start-up (v1rtc = 00) 01 v1 undervoltage detection at 80 % of nominal value at start-up (v1rtc = 01) 10 v1 undervoltage detection at 70 % of nominal value at start-up (v1rtc = 10) 11 v1 undervoltage detection at 60 % of nominal value at start-up (v1rtc = 11) 3 fnmc r/w forced normal mode control: 0 forced normal mode disabled 1 [1] forced normal mode enabled 2 sdmc r/w software development mode control: 0 [1] software development mode disabled 1 software development mode enabled 1:0 reserved r - table 9. watchdog status register (address 05h) bit symbol access value description 7:4 reserved r - 3 fnms r 0 sbc is not in forced normal mode 1 sbc is in forced normal mode 2 sdms r 0 sbc is not in software development mode 1 sbc is in software development mode 1:0 wds r watchdog status: 00 watchdog is off 01 watchdog is in first half of window 10 watchdog is in second half of window 11 reserved UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 12 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog 6.2.1 software development mode software development mode is provided to simplify the software design process. when software development mode is enabled, the watchdog starts up in autonomous mode (wmc = 001) and is inactive after a system reset, overriding the default value (see ta b l e 7 ). the watchdog is always off in autono mous mode if softwa re development mode is enabled (sdmc = 1; see ta b l e 1 0 ). software can be run without a watchdog in so ftware development m ode. however, it is possible to activate and deacti vate the watchdog for test purposes by selecting window or timeout mode via bits wmc while the sbc is in standby mode (note that window mode will only be activated when the sbc switches to normal mode). so ftware development mode is activated via bits sdmc in non-volatile memory (see ta b l e 8 ). 6.2.2 watchdog behavior in window mode the watchdog runs continuously in window mode. the watchdog will be in window mode if wmc = 100 and the UJA1164 is in normal mode. in window mode, the watchdog can only be triggered during the second half of the watchdog period. if the watchdog overflows, or is triggered in the first half of the watchdog period (before t trig(wd)1 ), a watchdog failure event is captured (if enabled) and a system reset is performed. after the s ystem reset, the watchdog failu re event is indicated in the system event status register (wdf = 1; see table 19 ). if the watchdog is triggered in the second half of the watchdog period (after t trig(wd)1 but before t trig(wd)2 ), the watchdog timer is restarted. 6.2.3 watchdog behavior in timeout mode the watchdog runs continuously in timeout mode. the watchdog will be in timeout mode if wmc = 010 and the UJA1164 is in normal or standby mode. the wa tchdog will also be in timeout mode if wmc = 100 and the UJA1164 is in standby mode. if autonomous mode is selected (wmc = 001), the watchdog will be in timeout m ode if one of the conditions for timeout mode listed in ta b l e 1 0 has been satisfied. in timeout mode, the watchdog timer can be reset at any time by a watchdog trigger. if the watchdog overflows, a watchdog failure event (wdf) is captured. if a wdf is already pending when the watchdog overflows, a syste m reset is performed. in timeout mode, the watchdog can be used as a cyclic wake-up source for the microcontroller when the UJA1164 is in standby mode. 6.2.4 watchdog behavior in autonomous mode autonomous mode is selected when wmc = 001. in autonomous mode, the watchdog is either off or in timeout mode, according to the conditions detailed in ta b l e 1 0 . table 10. watchdog status in autonomous mode UJA1164 operating mode watchdog status sdmc = 0 sdmc = 1 normal timeout mode off standby; rxd high off off any other mode off off standby; rxd low timeout mode off UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 13 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog when autonomous mode is selected, the watchdog will be in timeout mode if the sbc is in normal mode or standby mode with rxd low, provided software development mode has been disabled (sdmc = 0). otherwise the watchdog will be off. in autonomous mode, the watchdog will not be running when the sbc is in standby mode (rxd high). if a wake-up event is captured , pin rxd is forced low to signal the event and the watchdog is automatically restarted in timeout mode. 6.3 system reset when a system reset occurs, the sbc switch es to reset mode and initiates a process that generates a low-le vel pulse on pin rstn. 6.3.1 characteristics of pin rstn pin rstn is a bidirectional open drain low side driver with integrated pull-up resistance, as shown in figure 4 . with this configuration, the sbc can detect the pin being pulled down externally, e.g. by the microcon troller. a filter, with filter time t fltr(rst) , prevents a reset being triggered by noise etc. 6.3.2 selecting the reset pulse width the duration of the reset pulse is selected via bits rlc in the start-up control register ( ta b l e 11 ). the sbc distinguishes between a cold start and a warm start. a cold start is performed on start-up if the reset event was generated by a v1 undervoltage event. the reset pulse width for a cold start is determined by the setting of bits rlc. if the reset event was not triggered by a v1 undervoltage (e.g by a warm start of the microcontroller), the sbc always us es the shortest reset length (t w(rst) = 1 ms to 1.5 ms). fig 4. rstn internal pin configuration rstn v1 015aaa276 table 11. start-up control register (address 73h) bit symbol access value description 7:6 reserved r - 5:4 rlc r/w rstn reset pulse width: 00 [1] t w(rst) = 20 ms to 25 ms 01 t w(rst) = 10 ms to 12.5 ms 10 t w(rst) = 3.6 ms to 5 ms 11 t w(rst) = 1 ms to 1.5 ms 3:0 reserved r - UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 14 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog [1] factory preset value. 6.3.3 reset sources the following events will cause the uja1 164 to switch to reset mode: ? v v1 drops below the selected v1 undervoltage threshold defined by bits v1rtc ? pin rstn is pulled down externally ? the watchdog overflows in window mode ? the watchdog is triggered too early in window mode (before t trig(wd)1 ) ? the watchdog overflows in timeout mode with wdf = 1 (watchdog failure pending) ? an attempt is made to reconf igure the watchdog control register while the sbc is in normal mode ? the sbc leaves off mode ? the sbc leaves overtemp mode 6.4 global temperature protection the temperature of the UJA1164 is monitored continuously, except in off mode. the sbc switches to overtemp mode if the temperat ure exceeds the overte mperature protection activation threshold, t th(act)otp . in addition, pin rstn is driven low and v1 and the can transceiver are switched off. when the temperature drops below the overtemperature protection release threshold, t th(rel)otp , the sbc switches to standby mode via reset mode. in addition, the UJA1164 provides an overte mperature warning. when the ic temperature rises about the overtemperature warning threshold (t th(warn)otp ), status bit otws is set and an overtemperature warning event is captured (otw = 1). 6.5 power supplies 6.5.1 battery supply voltage (v bat ) the internal circuitry is supplied from the battery via pin bat. the device needs to be protected against negative supply voltages, e. g. by using an external series diode. if v bat falls below the power-off detection threshold, v th(det)poff , the sbc switches to off mode. however, the microcontroller supply voltage (v1) remains active until v bat falls below 2 v. the sbc switches from off mode to reset mode t startup after the battery voltage rises above the power-on detection threshold, v th(det)pon . power-on event status bit po is set to 1 to indicate the UJA1164 has powered up and left off mode (see table 19 ). 6.5.2 low-drop voltage supply for 5 v microcontroller (v1) v1 is intended to supply the microcontroller and the internal can transceiver and delivers up to 150 ma at 5 v. the output voltage on v1 is monitored. a system reset is generated if the voltage on v1 drops below the selected undervoltage threshold (60 %, 70 %, 80 % or 90 % of the nominal v1 output voltage, se lected via v1rtc in the v1 control register; see ta b l e 1 2 ). UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 15 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog the internal can transceiver consumes 50 ma (max) when the bus is continuously dominant, leaving 100 ma available for the extern al load on pin v1. in practice, the typical current consumption of the can transceiver is lower ( ? 25 ma), depending on the application, leaving more current available for the load. the default value of the undervoltage threshold at power-up is determined by the value of bits v1rtsuc in the sbc configuration control register ( ta b l e 8 ). the sbc configuration control register is in non-vo latile memory, allowing the user to define the undervoltage threshold (v1rtc) at start-up. in addition, an undervoltage warning (a v1u event; see section 6.8 ) is generated if the voltage on v1 falls below 90 % of the nominal value (and v1u event det ection is enabled, v1ue = 1; see ta b l e 2 3 ). this information can be used as a warning, when the 60 %, 70 % or 80 % threshold is selected, to indicate that the level on v1 is outside the nominal supply range. the status of v1, whether it is above or below the 90 % undervoltage threshold, can be read via bit v1s in the supply voltage status register ( table 13 ). [1] default value at power-up defined by setting of bits v1rtsuc (see table 8 ). [1] default value at power-up. 6.6 high-speed can transceiver the integrated high-speed can transceiver is designed for bit rates up to 1 mbit/s, providing differential transmit and receive capability to a can protocol controller. the transceiver is iso 11898-2 and iso 11898-5 compliant. the can transmitter is supplied from v1. the can transceiver supports autonomous can biasing as defined in iso 11898-6, which helps to minimize rf emissions. canh and canl are always biased to 2.5 v when the transceiver is in active or listen-only modes (cmc = 01/10/11). autonomous biasing is active in can offline mo de - to 2.5 v if there is activity on the bus (can offline bias mode) and to gnd if th ere is no activity on the bus for t > t to(silence) (can offline mode). table 12. v1 control register (address 10h) bit symbol access value description 7:2 reserved r - 1:0 v1rtc [1] r/w set v1 reset threshold: 00 reset threshold set to 90 % of v1 nominal output voltage 01 reset threshold set to 80 % of v1 nominal output voltage 10 reset threshold set to 70 % of v1 nominal output voltage 11 reset threshold set to 60 % of v1 nominal output voltage table 13. supply voltage status register (address 1bh) bit symbol access value description 7:1 reserved r - 0 v1s r/w v1 status: 0 [1] v1 output voltage above 90 % undervoltage threshold 1 v1 output voltage below 90 % undervoltage threshold UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 16 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog this is useful when the node is disabled due to a malfunction in the microcontroller. the sbc ensures that the can bus is correctly biased to avoid disturbing ongoing communication between other nodes. the au tonomous can bias voltage is derived directly from v bat . 6.6.1 can operating modes the integrated can transceiver supports f our operating modes: active, listen-only, offline and offline bias (see figure 6 ). the can transceiver operating mode depends on the UJA1164 operating mode and on the settin g of bits cmc in the can control register ( ta b l e 1 4 ). when the UJA1164 is in normal mode, the can transceiver operating mode (active, listen-only or offline) can be selected via bits cmc in the can control register ( ta b l e 1 4 ). when the sbc is in standby mode, the tr ansceiver is forced to offline mode. 6.6.1.1 can active mode in can active mode, the transceiver can transmit and receive data via canh and canl. the differential receiver converts the analog data on the bus lines into digital data, which is output on pin rxd. the transmitter conv erts digital data generated by the can controller (input on pin txd) into analog signals suitable for transmission over the canh and canl bus lines. the can transceiver is in active mode when: ? the UJA1164 is in normal mode (mc = 111) and the can transceiver has been enabled by setting bits cmc in the can mode control register to 01 or 10 (see ta b l e 1 4 ) and the voltage on pin v1 is above the 90 % threshold or ? the UJA1164 is in forc ed normal mode with v v1 > 90 % of nominal value if pin txd is held low (e.g. by a short-circuit to gnd) when can active mode is selected via bits cmc, the transceiver will not enter can active mode but will switch to or remain in can listen-only mode. it will remain in listen -only mode until pin txd goes high in order to prevent a hardware and/or software application failure from driving the bus lines to an unwanted dominant state. in can active mode, the can bias voltage is derived from v1. if v1 falls below the 90 % threshold, the UJA1164 exits can active mo de and enters can offline bias mode with autonomous can voltage biasing via pin bat. if, however, the sbc is in forced normal mode when v1 falls below the 90 % thre shold, the transceiver switches to can listen-only mode to ensure as much as possible of the sbc remains active during the ecu development phase. the application can determine whether the can tr ansceiver is ready to transmit data or is disabled by reading the can transmitter status (cts) bit in the transceiver status register ( ta b l e 1 5 ). 6.6.1.2 can listen-only mode can listen-only mode allows the UJA1164 to mo nitor bus activity while the transceiver is inactive, without influencing bu s levels. this facility could be used by development tools that need to listen to the bus but do not need to transmit or receive data or for UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 17 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog software-driven selective wake-up. dedicated microcontrollers could be used for selective wake-up, providing an embedded low-power can engine designed to monitor the bus for potential wake-up events. in listen-only mode the can transmitter is disabled, reducing current consumption. the can receiver and can biasing remain active . this enables the host microcontroller to switch to a low-power mode in which an embedded can protocol controller remains active, waiting for a signal to wake up the microcontroller. the can transceiver is in listen-only mode when: ? the UJA1164 is in normal mode and cmc = 11 or ? the UJA1164 is in forced normal mode and v v1 < 90 % of nominal value or ? the UJA1164 is in normal mode, cmc = 01 or 10 and v v1 < 90 % of nominal value 6.6.1.3 can offline and offline bias modes in can offline mode, the transceiver monitors the can bus for a wake-up event, provided can wake-up detection is enabled (cwe = 1). canh and canl are biased to gnd. can offline bias mode is the same as can offline mode, with the exception that the can bus is biased to 2.5 v. this mode is activa ted automatically when activity is detected on the can bus while the transceiver is in can offline mode. the tran sceiver will return to can offline mode if the can bus is silent (no can bus edges) for longer than t to(silence) . the can transceiver will switch from can ac tive mode to can offline bias mode if: ? the sbc switches to reset or standby mode or ? the sbc is in normal mode and cmc = 00 or ? v v1 < 90 % of nominal value the can transceiver will switch from can listen-only mode to can offline bias mode if: ? the sbc switches to reset or standby mode or ? the sbc is in normal mode and cmc = 00 the can transceiver switches to can offline mode: ? from can offline bias mode if no activity is detected on the bus (no can edges) for t> t to(silence) or ? when the sbc switches from off or overtemp mode to reset mode the can transceiver switches from can off line mode to can offline bias mode if: ? a wake-up event is detected on the can bus or ? the sbc is in normal mode, cmc = 01 or 10 and v v1 <90 % 6.6.1.4 can off the can transceiver is switched off comple tely with the bus lines floating when: ? the sbc switches to of f or overtemp mode or ? v bat falls below the can receiver undervoltage detection threshold, v uvd(can) UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 18 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog it will be switched on again on ente ring can offline mode when v bat rises above the undervoltage release threshold and the sbc is no longer in off/overtemp mode. 6.6.2 can standard wake-up if the can transceiver is in offline mode and can wake-up is enabled (cwe = 1), the UJA1164 will monitor the bu s for a wake-up pattern. a filter at the receiver input prevents unwanted wake-up events occurring due to automotive transients or emi. a dominant-recessive-dominant wake-up pattern must be transmitted on the can bus within the wake-up timeout time (t to(wake) ) to pass the wake-up filter and trigger a wake-up event (see figure 5 ; note that additional pulses may occur between the recessive/dominant phases). the recessive and dominant phases must last at least t wake(busrec) and t wake(busdom) , respectively. when a valid can wake-up pattern is detected on the bus, wake-up bit cw in the transceiver event status register is set (see ta b l e 2 1 ) and pin rxd is driven low. fig 5. can wake-up timing t dom t wake(busdom) recessive t rec t wake(busrec) t dom t wake(busdom) dominant dominant 015aaa267 t wake < t to(wake) can wake-up UJA1164 all information provided in this document is subject to legal disclaimers. ? nxp b.v. 2013. all rights reserved. product data sheet rev. 1 ? 5 august 2013 19 of 52 nxp semiconductors UJA1164 mini high-speed can s ystem basis chip wi th standby mode & watchdog (1) to prevent the bus lines being driven to a permanent dominant stat e, the transceiver will not switch to can active mode if p in txd is held low (e.g. by a short-circuit to gnd) (2) when cmc = 01, a v1 undervoltage event (v v1 < 90 %) will cause the transceiver to exit active mode and the transmitter will be switched off. when cmc = 10, the transceiver will not immediately leave active mode in response to a v1 undervoltage event; the transmitter will remain active until the v1 reset threshold has been reached, when the sbc will switch to reset mode and the transceiver will switch to ca n offline or can offline bias mode. fig 6. can transceiver state machine & |