Low Power Modes with Periodic/Real-time Clock Wake-up
Contents
1. Considerations When Entering Power Down Mode 4 In XC83x or Power Down Mode 2 In XC82x In both modes the RTC and 75 kHz oscillator are not powered down The Watchdog Timer WDT clocked by the 75 kHz oscillator will also be running if it was enabled before entering this mode As the microcontroller will not be able to wake up and return to active mode when the watchdog timer overflows it is mandatory to disable the WDT before entering these two power down modes As for the RTC it must be programmed to run in RTC Mode 1 Periodic Wake up Mode before the entry to power down In this RTC mode the real time clock operates with the 75 kHz oscillator running in the periodic wake up mode and the real time count is maintained The RTC counter is reset and the count starts from zero every time the RTC triggers a wake up from power down mode Considerations When Entering Power Down Mode 2 In XC83x describes the RTC setup except the RTC must be set to mode 1 instead of mode 0 before entering these two modes The calculation for periodic wake up time setup is 1 t _ CCVAL CNTVAL x 512 wake up EE GS000 where e CNTVAL Counter values in CNTx registers e CCVAL Compare values in RTCCR x registers Although the 75 kHz oscillator is running in these two power down modes it is not possible to monitor the status of the 75 kHz oscillation because the oscillator watchdog is powered down Application Note 13 V1 1 2010 08 a AP08098 i2. e When bit XTAL2L is 0 select the RTC Mode 0 e Configure and enable the RTC e Disable the WDT module e Select power down mode 2 e Enter power down mode Considerations When Entering Power Down Mode 2 In XC83x The RTC 75 kHz oscillator and 32 768 kHz oscillator pad are not shut down in power down mode 2 The Watchdog Timer WDT which is clocked by the 75 kHz oscillator will also be running if it was enabled before entering this mode Because the microcontroller will not be able to wake up and return to active mode when the Watchdog Timer overflows in power down mode it is mandatory to disable the WDT before the entry to power down mode 2 The RTC must be programmed to run in Mode 0 i e it must be in time keeping mode before the entry to power down mode 2 In this RTC mode the real time clock operates with the 32 768 kHz oscillator input and the real time count is maintained The RTC is not reset and continues to run when the RTC triggers a wake up from power down mode 2 To wake up from power down mode without reset using the RTC wake up event register RTCCRx must be setup before entering power down mode If the RTC is required to wake up the microcontroller from power down mode 2 the following RTC configuration should be executed before setting the microcontroller to that mode e Set RTC to mode 0 e Set RTC starting value e Set compare capture register RTCCRO RTCCR3 value to define the time period after which the microco
3. ANL RTC RTCON 0xF9 select RTC mode 0 configure RTC count clock register CNTO 3 MOV SCU PAGE 0x01 MOV PASSWD 0x98 Register RTC_CNTx are protected open protection MOV RTC_CNT0 0x00 set the RTC start value MOV RTC_CNT1 0x00 MOV RTC_CNT2 0x00 MOV RTC_CNT3 0x00 MOV PASSWD 0xA8 close protection configure RTC compare capture register value MOV RTC_RTCCRO 0x00 MOV RTC_RTCCR1 0x06 MOV RTC _RTCCR2 0x00 MOV RTC_RTCCR3 0x00 enable RTC ORL RTC RTCON 0x01 start RTC operation MOV SCU_PAGE 0x01 MOV PASSWD 0x98 open protection ANL WDTCON 0xFB MOV PASSWD 0xA8 close protection set microcontroller to PD mode 2 MOV SCU_PAGE 0x01 ANL PMCONO OxF3 ORL PMCONO 0x04 select PD2 MOV PASSWD 0x98 open protection ORL PMCONO 0x02 Power Down Mode Enable NOP 2 NOPsS are required after setting PD 2 when wake up without reset NOP MOV PASSWD 0xA8 close protection Application Note 11 V1 1 2010 08 eo e AP08098 in fi n eon Low Power Modes with Periodic Real time Clock Wake up in XC82x XC83x 3 3 Using Power Down Mode 3 In XC83x The sequence to enter power down mode 3 is e Power up the 32 768 kHz oscillator pad e Wait for 2 seconds for the oscillation to be stable e Select the RTC Mode 0 e Configure and enable the RTC e Disable the WDT module optional e Select power down mode 3 e Enter power down mode Considerations When Entering Power Down Mode 3
4. Citi Infineon XC800 Family AP08098 Low Power Modes with Periodic Real time Clock Wake up in XC82x XC83x Application Note V1 1 2010 08 Microcontrollers Edition 2010 08 Published by Infineon Technologies AG 81726 Munich Germany 2010 Infineon Technologies AG All Rights Reserved LEGAL DISCLAIMER THE INFORMATION GIVEN IN THIS APPLICATION NOTE IS GIVEN AS A HINT FOR THE IMPLEMENTATION OF THE INFINEON TECHNOLOGIES COMPONENT ONLY AND SHALL NOT BE REGARDED AS ANY DESCRIPTION OR WARRANTY OF A CERTAIN FUNCTIONALITY CONDITION OR QUALITY OF THE INFINEON TECHNOLOGIES COMPONENT THE RECIPIENT OF THIS APPLICATION NOTE MUST VERIFY ANY FUNCTION DESCRIBED HEREIN IN THE REAL APPLICATION INFINEON TECHNOLOGIES HEREBY DISCLAIMS ANY AND ALL WARRANTIES AND LIABILITIES OF ANY KIND INCLUDING WITHOUT LIMITATION WARRANTIES OF NON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OF ANY THIRD PARTY WITH RESPECT TO ANY AND ALL INFORMATION GIVEN IN THIS APPLICATION NOTE Information For further information on technology delivery terms and conditions and prices please contact the nearest Infineon Technologies Office www infineon com Warnings Due to technical requirements components may contain dangerous substances For information on the types in question please contact the nearest Infineon Technologies Office Infineon Technologies components may be used in life support devices or systems only with the express written appr
5. WAIT 32 STABLE MOV A OSC_CON JB ACC 4 WAIT 32 STABLE iRTC configuration ANL RTC RTCON 0xF9 select RTC mode 0 configure RTC count clock register CNTO 3 MOV SCU_PAGE 0x01 MOV PASSWD 0x98 Register RTC _CNTx are protected open protection MOV RTC_CNTO 0x00 set the RTC start value MOV RTC_CNT1 0x00 MOV RTC_CNT2 0x00 MOV RTC_CNT3 0x00 MOV PASSWD 0xA8 close protection configure RTC compare capture register value MOV RTC_RTCCRO 0x00 MOV RTC_RTCCR1 0x06 Application Note 12 V1 1 2010 08 eo e AP08098 in fi n eon Low Power Modes with Periodic Real time Clock Wake up in XC82x XC83x MOV RTC_RTCCR2 000 MOV RTC_RTCCR3 000 enable RTC ORL RTC RTCON 0x01 start RTC operation disable WDT MOV SCU_PAGE 0x01 MOV PASSWD 0x98 open protection ANL WDTCON 0xFB MOV PASSWD 0xA8 close protection set microcontroller to PD mode 3 MOV SCU_PAGE 0x01 ANL PMCONO OxF3 ORL PMCONO 0x08 select PD3 MOV PASSWD 0x98 open protection ORL PMCONO 0x02 Power Down Mode Enable NOP 72 NOPsS are required after setting PD 3 when wake up without reset NOP MOV PASSWD 0xA8 close protection 3 4 Using Power Down Mode 4 In XC83x and Power Down Mode 2 In XC82x The sequence to enter XC83x power down mode 4 or XC82x power down mode 2 is e Configure and enable RTC e Disable the WDT module Select XC83x power down mode 4 or XC82x power down mode 2 Enable power down mode
6. to active mode from the power down state In addition this bit can also be used to distinguish between a wake up with reset from power down mode and other type of resets i e power on reset POR In the wake up with reset mode all registers are reset to default values after wake up except for this bit Wake up flags are listed in Table 5 Table 5 Wake up Flags with Different Wake up Sources Wake up sources RST_RTCON CFRTC OSC_CON XTAL2L RSTCON WKRS EXINTO 0 0 1 with or without reset RTC 1 0 1 with or without reset Loss of External Oscillation 0 1 1 with or without reset Application Note 8 V1 1 2010 08 eo e AP08098 in fi n eon Low Power Modes with Periodic Real time Clock Wake up in XC82x XC83x Considerations On Waking Up From Power Down Mode On waking up from power down mode without reset the CPU starts to run from the instruction following the one that sets the PD bit User code must include two NOP instructions immediately after the instructions that sets the PD bit This ensures that the first instruction after the two NOP instructions is executed correctly after wake up from power down mode Another consideration is to give at least 500 usec between the time that bit PMCONO PD is set to the triggering of the wake up A shorter time will not result in any saving in power consumption because this is the amount of time needed to shut down all the unused modules 3 1 Using Power Down Mode
7. 1 In XC82x XC83x To enter power down mode 1 the following sequence is recommended e Disable the WDT module optional e Disable the RTC module optional e Configure wake up source external interrupt 0 including the selection of external interrupt 0 input pin and external interrupt 0 trigger select e Select power down mode 1 where all modules are powered down including the 48 MHz and 75 kHz oscillators Considerations When Entering Power Down Mode 1 In XC82x XC83x In power down mode 1 the shutting down of the 75 kHz oscillator causes the RTC and Watchdog Timer WDT module which uses this oscillator to clock their respective counter timer to stop running If the user intends to use these 2 modules after the microcontroller wakes up without a reset it is recommended to disable the RTC and WDT module by software before entering power down mode and only to enable them again after exiting from power down mode This is to avoid any inaccurate counting because the 75 kHz oscillator usually starts to run with an inaccurate frequency on waking up Considerations On Waking up from Power Down Mode 1 In XC82x XC83x After wake up from power down mode without reset ensure that the 48 MHz and 75 kHz oscillators are stable after power up by checking the status of the OSC_CON INTOSC_ST status flag It is recommended to enable the WDT and RTC module only after this bit is set to 1 In addition the oscillator watchdog which monitors the behavior of the
8. 32 768 kHz external clock in the XC83x an oscillator watchdog operating with a 75 kHz internal clock must be set up to run in the XC83x power down mode 2 Note A failure in 32 768 kHz external oscillator is detected when it is running below 16 kHz typical Wake up Modes In XC82x XC83x there are 2 types of wake up from each power down mode e Wake up with reset e Wake up without reset When wake up with reset is selected the system will execute a reset sequence similar to the power on reset sequence The CPU starts running code from the beginning of the Flash code memory This mode is useful when the user wants a defined state for all the registers and modules in the microcontroller after wake up When wake up without reset is selected a fast wake up sequence is implemented which means that the CPU program counter will continue to run from the point at which it was stopped Wake up Sources To wake up from power down mode one or more sources are available for each power down mode as shown in Table 3 for XC82x and Table 4 for XC83x In power down mode 1 wake up can only be triggered by toggling the external interrupt 0 pin For the rest of the power down mode RTC is running using either the 32 768 kHz external oscillator or the 75 kHz internal oscillator so wake up can also be triggered when the RTC counter reaches a predefined time It allows the microcontroller to exit power down mode and enter active mode after a specific period of
9. In XC83x As with power down mode 1 shutting down the 75 kHz oscillator causes the Watchdog Timer WDT module to stop running in power down mode 3 Considerations for WDT during power down mode are described in Considerations When Entering Power Down Mode 1 In XC82x XC83x In power down mode 3 the RTC and 32 768 kHz oscillator pad are not powered down However no monitoring of the status of the external oscillation is possible in this mode In the event of the loss of the external OSC the RTC will not be able to wake up the microcontroller from power down mode 3 It is therefore recommended to enable the external interrupt wake up resource before entering power down mode 3 As for the RTC it must be programmed to run in RTC Mode 0 Considerations When Entering Power Down Mode 2 In XC83x describes the setup of RTC for power down mode 3 Considerations On Waking up from Power Down Mode 3 To exit power down mode 3 the real time clock wake up event can be used if the external oscillation is stable It can also be woken when it receives an external wake up signal via the EXINTO pin by setting the EWS bit to 1 in the PMCONO register The use of WDT after wake up without reset from power down mode 3 is described in Considerations On Waking up from Power Down Mode 1 In XC82x XC83x Demonstration Code Example for XC83x power down mode 3 entry and exit enable 32 768kHz oscillator MOV SCU PAGE 0x01 ANL OSC_CON 0xDF
10. e microcontroller wakes up every 10 seconds using the periodic wake up function and enters power down mode again after 500 us In XC83x_example output 1 of P1 5 indicates that the microcontroller is in active mode The microcontroller wakes up every 4 seconds using the real time clock wake up function and enters power down mode again after 500 us The microcontroller is also configured to wake up by a rising edge on PO 5 or by a failure in the 32 768 kHz external oscillator Application Note 15 V1 1 2010 08
11. e system clock frequency of either 8 MHz or 24 MHz From active mode different power saving modes can be selected by software They are e Idle mode XC82x and XC83x e Power down mode 1 XC82x and XC83x e Power down mode 2 XC82x and XC83x e Power down mode 3 XC83x e Power down mode 4 XC83x Once the microcontroller wakes up exits from these modes it returns to active mode 2 1 Idle Mode The idle mode is used to reduce power consumption by stopping the CPU s clock Oscillators and enabled peripherals remain functional Refer to the User s Manual for more details of this mode 2 2 Power Down Mode In order to achieve different levels of operation that reduce power consumption the XC82x has built in two types of power down mode while the XC83x has four power down modes In these modes most of the modules are disabled and powered down while the contents of the on chip memories are maintained Table 1 and Table 2 show the modules that are still running during power down mode in XC82x and XC83x respectively Modules which are not referenced in the table are not active in these modes Table 1 XC82x Module Behavior in Power Down Mode Modules Power Down Mode 1 Power Down Mode 2 Low Power Embedded Voltage Regulator Running Running Real Time Clock Shut down Running in RTC Mode 1 75 kHz On chip Oscillator Shut down Running Application Note 5 V1 1 2010 08 Infineon AP08098 Low Power Modes with Peri
12. e up Not available Available Available Not available 32 678 kHz Clock failure Not available Available Not available Not Available EXINTO Available Available Available Available 1 This wake up source will not be available if the RTC clock stops runnning Besides the EXINTO and RTC wake up sources XC83x power down mode 2 has an additional wake up source as shown in Table 4 A clock failure in the 32 768 kHz external clock will trigger the microcontroller to wake up from power down mode 2 This can be seen as an advantage compared to the power down mode 3 If there is a clock failure in power down mode 3 the RTC wake up source is not available and so the microcontroller can only be woken up by an external trigger EXINTO Comparison between Power Down Modes The XC83x current consumption in power down modes 2 3 and 4 is approximately 2 uA 3 UA typically higher than power down mode 1 because more built in modes are running to support the real time clock and periodic wake up functions Similarly the XC82x power down mode 2 is approximately 2 uA higher than power down mode 1 While the current consumption of the XC83x power down modes 3 and 4 are quite similar power down mode 2 has the highest current consumption in that microcontroller The main advantage of power down modes 2 3 and 4 is that the length of time that the microcontroller stays in power down mode can be easily configured to achieve the required average power c
13. ion ANL WDTCON 0xFB MOV PASSWD 0xA8 close protection set microcontroller to PD mode 2 MOV SCU_PAGE 0x01 ANL PMCONO 0xF3 ORL PMCONO 0x04 select PD2 MOV PASSWD 0x98 open protection ORL PMCONO 0x02 Power Down Mode Enable NOP 2 NOPs are required after setting PD 2 when wake up without reset NOP MOV PASSWD 0xA8 close protection For XC83x power down mode 4 the example code above can be reused The only difference is to set PMCONO PDMODE to 11 Application Note 14 V1 1 2010 08 eo fi AP08098 In In eon Low Power Modes with Periodic Real time Clock Wake up in XC82x XC83x 4 Demonstration Software Wake up from Power Down Mode 2 Two sets of example code are provided with this application note The XC82x_example self extracting EXE file demonstrates waking the microcontroller from power down mode 2 using the periodic wake up function The XC83x_example exe demonstrates waking the microcontroller from power down mode 2 using the real time clock wake up function A 32 768 kHz clock failure event or external interrupt event will also wake up the microcontroller The application examples are implemented and verified using the following hardware and software components e XC82x XC83x easy kit boards e Infineon DAVE tool for code generation e DAvE Bench for code compilation Infineon XC800_FLOAD for code downloading In XC82x_example output 1 of P1 2 indicates that the microcontroller is in active mode Th
14. ke up source Each port signal that goes into the microcontroller will be held at the last state when the power down mode was activated If the user intends to maintain a level of 1 or O on the output pin during power down the internal pull up pull down device should be enabled before entering power down mode Upon wake up the port pins will be enabled as per the SFR setting Flash Handling In Power Down Mode Flash memory is shut down in power down mode regardless of the current flash activity i e program erase operation It is therefore recommended to ensure that all flash program or erase operations are completed before entering the power down mode For a situation where power down mode must be entered immediately it is recommended to repeat the previous flash operation after waking up from power down mode Wake up Flags When a wake up from power down mode without reset is selected the status flag of the wake up event can be used to indicate the wake up source e wake up by RTC bit RTC_RTCON CFRTC is set to 1 e wake up by external interrupt 0 bit CFRTC is 0 e wake up by loss of external 32 768kHz oscillation OSC_CON XTAL2 flag is set to 1 Note that interrupt servicing of the wake up event is not supported Checking of the status bit is useful when an application needs to perform a different task for each source of wake up The status wake up indication bit RSTCON WKRS is used to indicate that the microcontroller has exited
15. n fi n eon Low Power Modes with Periodic Real time Clock Wake up in XC82x XC83x Considerations On Waking up from Power Down Mode 4 In XC83x or Power Down Mode 2 In XC82x Besides the real time clock wake up event the microcontroller can also be woken on receipt of external wake up signal via the EXINTO pin by setting the EWS bit to 1 in the PMCONO register After wake up from power down mode without reset the WDT module and Oscillator Watchdog WDT can be re enabled if necessary as explained in Considerations On Waking up from Power Down Mode 1 In XC82x XC83x For subsequent entry to the XC82x power down mode 2 or the XC83x power down mode 4 the RTC does not require setup again if the time planned to stay in power down and active mode remains the same Demonstration Code Example for XC82x power down mode 2 entry and exit RTC configuration ORL RTC RTCON 0x04 select RTC mode 1 configure RTC count clock register CNTO 3 MOV SCU PAGE 0x01 MOV PASSWD 0x98 Register RTC_CNTx are protected open protection MOV RTC_CNT0 0x00 set the RTC start value MOV RTC_CNT1 0x00 MOV RTC_CNT2 0x00 MOV RTC_CNT3 0x00 MOV PASSWD 0xA8 close protection configure RTC compare capture register value MOV RTC_RTCCRO 0x00 MOV RTC RTCCRL 0x06 MOV RTC _RTCCR2 0x00 MOV RTC_RTCCR3 0x00 enable RTC ORL RTC RTCON 0x01 start RTC operation disable WDT MOV SCU_PAGE 0x01 MOV PASSWD 0x98 open protect
16. ntroller should be woken up from power down mode 2 e Enable RTC It is possible to monitor the status of the external oscillation in power down mode 2 as the 32 768 kHz Oscillator Watchdog OWD is enabled in power down mode 2 Although the 75 kHz oscillator is also running in power down mode 2 it is not possible to monitor the oscillation because its Watchdog is powered down Considerations On Waking up from Power Down Mode 2 In XC83x To exit power down mode 2 besides the real time clock wake up event it is also possible to exit on receipt of an external wake up signal via EXINTO pin if EWS bit is set to 1 in PMCONO register In the event of the loss of external 32 768kHz oscillation power down mode 2 will be exited when the OSC_CON XTALA2L flag is set to 1 Application Note 10 V1 1 2010 08 eo e AP08098 in fi n eon Low Power Modes with Periodic Real time Clock Wake up in XC82x XC83x In addition after wake up from power down mode without reset the WDT module and oscillator watchdog can be re enabled if necessary as explained in Considerations On Waking up from Power Down Mode 1 In XC82x XC83x Demonstration Code Example for XC83x power down mode 2 entry and exit enable 32 768kHz oscillator and OWD MOV SCU_PAGE 0x01 ANL OSC_CON 0xDF WAIT 75 STABLE MOV A OSC_CON JNB ACC 6 WAIT 75 STABLE ORL OSC_CON 0x08 WAIT 32 STABLE MOV A OSC_CON JB ACC 4 WAIT 32 STABLE RTC configuration
17. odic Real time Clock Wake up in XC82x XC83x Table 2 XC83x Module Behavior in Power Down Mode Modules Power Down Power Down Power Down Power Down Mode 1 Mode 2 Mode 3 Mode 4 Low Power Embedded Voltage Regulator Running Running Running Running Real Time Clock Shut down Running in Running in Running in RTC Mode 0 RTC Mode 0 RTC Mode 1 32 768 kHz Oscillator Pad Shut down Running Running Shut down 32 768 kHz Oscillator Watchdog Shut down Running Shut down Shut down 75 kHz On chip Oscillator Shut down Running Shut down Running The only current consumption in power down mode 1 is from the Low Power Embedded Voltage Regulator LPEVR The LPEVR is required to maintain memory contents and to facilitate a fast wake up from power down to active mode In power down modes 2 3 and 4 the Real Time Clock RTC and RTC clock source will also be running in addition to the LPEVR The RTC has 2 operating modes e RTC mode 0 uses the 32 768 kHz external oscillator via the oscillator pad RTC mode 1 uses the 75 kHz internal oscillator clock as the RTC clock input Both RTC modes are available in the XC83x but mode 0 is not available on the XC82x because it does not support the 32 768 kHz external oscillation The power down mode and RTC mode must be enabled and configured to the respective mode see Table 1 for XC82x and Table 2 for XC83x before entering power down mode Note that in order to detect the failure of the
18. on Note 4 V1 1 2010 08 eo AP08098 in fi n eon Low Power Modes with Periodic Real time Clock Wake up in XC82x XC83x 1 Introduction Dynamically changing the microcontroller operating mode is one way to achieve the lowest average power consumption For example when the microcontroller needs to perform a computationally intensive task the microcontroller can run as fast as possible for the shortest possible time When there are no tasks to perform a low current consumption power down mode can be entered where as much of the microcontroller as possible is switched off Based on this approach the XC82x XC83x 8 bit microcontroller has additional built in power saving modes such as power down mode with periodic wake up or real time clock wake up functions to help achieve the lowest possible power consumption These features provide flexibility for the user and offer ideal control for many applications especially sensor and fail safe applications This Application Note provides guidelines and information for the use and setup of the available power down modes Two examples are also included One example is used to illustrate the power down mode with periodic wake up function in the XC82x while a second example illustrates the power down with real time clock wake up function in the XC83x 2 Overview Power management After reset the active operating mode normal operating mode is entered in which the CPU is active and running in th
19. onsumption A feature of the XC83x power down mode 2 is the additionally enabled oscillator watchdog that is used to wake up the microcontroller when there is a 32 768 clock failure If the application is able to take the additional 1 uA 2 UA typicial current this is a preferred power down mode as compared to the mode 3 Refer to the Data Sheet and AP08101 for more information on power down current Application Note 7 V1 1 2010 08 eo e AP08098 in fi n eon Low Power Modes with Periodic Real time Clock Wake up in XC82x XC83x 3 Using Power Down Mode To enter power down mode follow the steps listed here Settings for the specific power down modes are given in Section 3 1 Section 3 2 Section 3 3 and Section 3 4 e Configure wake up source Refer to Section 3 1 Section 3 2 Section 3 3 and Section 3 4 e Select the type of power down mode Select wake up mode with reset or without reset Enable power down mode General code execution sequence for power down mode entry MOV SCU_PAGE 0x01 ORL PMCONO 0x04 select PD mode 2 ORL PMCONO 0x10 wake up with reset mode is selected MOV PASSWD 0x98 open protection PD bit is a protected bit ORL PMCONO 0x02 Power Down Mode Enable MOV PASSWD 0xA8 close protection Pin Status In Power Down Mode In power down mode pin handling is transparent to the user All port pins are disabled except for the external interrupt O pin if it is enabled as a wa
20. oval of Infineon Technologies if a failure of such components can reasonably be expected to cause the failure of that life support device or system or to affect the safety or effectiveness of that device or system Life support devices or systems are intended to be implanted in the human body or to support and or maintain and sustain and or protect human life If they fail it is reasonable to assume that the health of the user or other persons may be endangered eo fi AP08098 In In eon Low Power Modes with Periodic Real time Clock Wake up in XC82x XC83x XC82x XC83x Revision History V1 1 2010 08 Previous Version s V1 0 Page Subjects major changes since last revision Page 5 An overview of the power saving modes in XC83x has been added in Chapter 2 Page 8 Added a description of the loss of external oscillation wake up flag that are used in XC83x Page 9 Added a description on the considerations during waking up from all power down modes in XC82x and XC83x Page 9 Update Chapter 3 1 to include the usage of XC83x power down mode 1 Page 10 Added Chapter 3 2 and 3 3 on the usage of XC83x power down mode 2 and 3 Page 12 Page 13 Added a description of the XC83x power down mode 4 in Chapter 3 4 This mode has the same behaviors as XC82x power down mode 2 Page 13 WDT must be disabled before entering XC82x power down mode 2 or XC83x power down mode 4 because a timer overflows in power down mode would p
21. revent the microcontroller from waking up Page 15 Two C codes XC82x_example and XC83x_example have been added in Chapter 4 The assembly code found in the previous version V1 0 has similiar behaviors as the XC82x_example and it can also be used to illustrate the usage of XC82x power down mode 2 We Listen to Your Comments Is there any information in this document that you feel is wrong unclear or missing Your feedback will help us to continuously improve the quality of this document Please send your proposal including a reference to this document to mcdocu comments infineon com gt lt Application Note 3 V1 1 2010 08 oe fi AP08098 In In eon Low Power Modes with Periodic Real time Clock Wake up in XC82x XC83x Table of Contents 1 Introduction EE dae ER a ae eee he fae aleve age ale EGO SE ee Baad 5 2 Overview Power management 00 0 cee eee tee 5 2 1 Idle le MEE ined a ed Re ee ee ace id eh oa CA ee a OE EG 5 2 2 Power Down Mode aeia nama Re oi hee Sede Da NR a ele ee ba a ea hae We had a 5 3 Using Power Down Mode 0 000 tenet ae 8 3 1 Using Power Down Mode 1 In XC82x XC83X EE eee 9 3 2 Using Power Down Mode 2 In XC83X cee eee 10 3 3 Using Power Down Mode 3 In XC83X eens 12 3 4 Using Power Down Mode 4 In XC83x and Power Down Mode 2 In XC82x 13 4 Demonstration Software Wake up from Power Down Mode 2 15 Applicati
22. se 2 oscillators can also be re enabled by setting bit OSC_CON RCOWDRST Demonstration Code Example for power down mode 1 entry and exit Disable WDT MOV SCU_ PAGE 0x01 MOV PASSWD 0x98 open protection WDTEN is a protected bit ANL WDTCON 0xXFB MOV PASSWD 0xA8 close protection Disable RTC ANL RTC RTCON OXFE Configure external interrupt 0 as wake up event iPO 5 pin is the default external interrupt 0 MOV SCU_PAGE 0x01 enable external interrupt 0 wake up resourc ANL PMCONO OxFE ORL PMCONO 0x01 set bit EWS to 1 MOV SCU_PAGE 0x00 ANL EXICONO OxFC ORL EXICONO 0x01 set rising edge to trigger external interrupt 0 Select power down mode 1 Application Note 9 V1 1 2010 08 eo e AP08098 in fi n eon Low Power Modes with Periodic Real time Clock Wake up in XC82x XC83x MOV SCU_ PAGE 0x01 ANL PMCONO 0xFB select PD mode 1 Enable power down mode MOV PASSWD 0x98 open protection PD bit is a protected bit ORL PMCONO 0x02 Power Down Mode Enable NOP 72 NOPS are required after setting PD 1 when wake up without reset NOP MOV PASSWD 0xA8 close protection 3 2 Using Power Down Mode 2 In XC83x The sequence to enter power down mode 2 is Power up the 32 768 kHz oscillator pad e Wait for 2 seconds for the oscillation to be stable Ensure that the 75 kHz oscillator is stabled before enabling the 32 768 kHz OWD e Restart the 32 768 kHz OWD
23. time With this function dynamically changing the operating mode of the microcontroller can be achieved with minimum software setup There are 2 types of wake up sources generated from the RTC module e Periodic wake up e Real time clock RTC wake up Application Note 6 V1 1 2010 08 eo AP08098 in fi n eon Low Power Modes with Periodic Real time Clock Wake up in XC82x XC83x Both wake up sources are available in XC83x as shown in Table 4 The XC83x power down modes 2 and 3 support a real time clock wake up function with the RTC running in mode 0 The periodic wake up function is available in the XC83x power down mode 4 In XC82x the real time clock wake up is not available see Table 3 However the periodic wake up function is available in power down mode 2 with the RTC running in mode 1 The XC82x power down mode 2 and the XC83x power down mode 4 have the same behavior Table 3 Available Wake up Sources for Power Down Mode in XC82x Power Down Mode 2 Available Available Wake up Sources Power Down Mode 1 Periodic wake up Not available EXINTO Available 1 This wake up source will not be available if the RTC clock stops runnning Table 4 Available Wake up Sources for Power Down Mode in XC83x Wake up Sources Power Down Power Down Power Down Power Down Mode 1 Mode 2 Mode 3 Mode 4 Periodic wake up Not available Not available Not available Available Real time Clock wak
Download Pdf Manuals
Related Search