Infineon XC800 Series Manual
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- Using manual (31 pages) ,
- Application note (22 pages) ,
- User manual (461 pages)
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Summary of Contents for Infineon XC800 Series
- Page 1 Application Note, V1.0, Dec. 2006 A P 0 8 0 5 6 XC800 Family P o w e r S a v i n g F e a t u r e s - A c h i e v i n g L o w P o w e r R e q u i r e m e n t s o n A p p l i c a t i o n s M i c r o c o n t r o l l e r s...
- Page 2 Infineon Technologies Components may only be used in life-support devices or systems with the express written approval 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.
- Page 3 Any information within this document that you feel is wrong, unclear or missing at all? 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 Application Note V1.0, 2006-12...
- Page 4 AP08056 Power Saving Features Overview Overview This application note describes the various power saving features in the XC800 architecture. It is intended to provide users of the XC866 and XC886/888 with information and guidelines on how to apply these features to achieve low power consumption requirements on applications via a combination of techniques which include: •...
- Page 5 AP08056 Power Saving Features Stopping the CPU Clock (Idle Mode) Stopping the CPU Clock (Idle Mode) The microcontroller can reduce power consumption by stopping the CPU’s clock. This can be achieved by putting the device in idle mode. In this mode, the oscillator continues to run, but the CPU is stopped with its clock disabled.
- Page 6 AP08056 Power Saving Features Stopping the CPU Clock (Idle Mode) The device in idle mode can be exited to active mode on the occurrence of any of the two conditions: 1. Hardware reset. The device is put into the hardware reset state. 2.
- Page 7 AP08056 Power Saving Features Reducing Clock Speed (Slow-Down Mode) Reducing Clock Speed (Slow-Down Mode) The slow-down mode is used to reduce the power consumption by dividing the CPU clock and the peripherals clock with a programmable factor. The slow-down mode is activated by setting the bit PMCON0.SD after the programmable factor in the bitfield CMCON.CLKREL has been selected.
- Page 8 AP08056 Power Saving Features Reducing Clock Speed (Slow-Down Mode) Combining slow-down Mode with Idle Mode The slow-down mode can be combined with the idle mode (slow-down-idle mode). This can be done by performing the following sequence: 1. Select the slow-down frequency in the bitfield CMCON.CLKREL. 2.
- Page 9 AP08056 Power Saving Features Reducing Clock Speed (Slow-Down Mode) Table 3 Current comparison between slow-down mode and slow-down-idle mode of a XC866-1FR device = 80.4 MHz Current (mA) Peripheral CLKREL Slow-Down Slow-Down- Difference Frequency (MHz) Idle (Y) X - Y 26.800 0000 15.50...
- Page 10 AP08056 Power Saving Features Reducing Clock Speed (Slow-Down Mode) Table 4 Current comparison between slow-down mode and slow-down-idle mode of a XC866-4FR device = 79.84 MHz Current (mA) Peripheral CLKREL Slow-Down Slow-Down- Difference Frequency (MHz) Idle (Y) X - Y 26.613 0000 17.84...
- Page 11 AP08056 Power Saving Features Reducing Clock Speed (Slow-Down Mode) Table 5 Current comparison between slow-down mode and slow-down-idle mode of a XC886 device = 97.50 MHz Current (mA) Peripheral CLKREL Slow-Down Slow-Down- Difference Frequency (MHz) Idle (Y) X - Y 24.375 0000 23.46...
- Page 12 AP08056 Power Saving Features Reducing Clock Speed (Slow-Down Mode) Table 6 Current comparison between slow-down mode and slow-down-idle mode of a XC888 device = 96.50 MHz Current (mA) Peripheral CLKREL Slow-Down Slow-Down- Difference Frequency (MHz) Idle (Y) X - Y 24.125 0000 23.22...
- Page 13 AP08056 Power Saving Features Power Down of the Entire System (Power-Down Mode) Power Down of the Entire System (Power-Down Mode) Power-down of the entire system can be achieved by setting the device in power-down mode. In this mode, all functions of the microcontroller are stopped and only the contents of the FLASH, on-chip RAM, XRAM and the SFRs are maintained.
- Page 14 AP08056 Power Saving Features Power Down of the Entire System (Power-Down Mode) STACKSP = SP; //Save current stack pointer at an absolute memory //location. e.g. unsigned char idata STACKSP _at_ //0xe0; iram location 0xe0 = 0x42 SCU_PAGE = 0x01;//Open SCU page 1 to access PMCON0 and PASSWD PASSWD = 0x98;...
- Page 15 AP08056 Power Saving Features Power Down of the Entire System (Power-Down Mode) If bit WKSEL was cleared to 0 before entering power-down mode, a fast wake-up sequence is used. The port pins continue to hold their state which was valid during power-down mode until they are affected by program execution.
- Page 16 AP08056 Power Saving Features Stopping the Clocks of Individual System Components Stopping the Clocks of Individual System Components (Peripheral Management) Peripherals which are not required for a particular functionality can be disabled by programming the assigned register bits in PMCON1 and PMCON2 which would gate off clock inputs.
- Page 17 AP08056 Power Saving Features Stopping the Clocks of Individual System Components Table 9 Current consumption by the peripherals of a XC866-4FR device at different peripheral clock (PCLK) frequencies Current (mA) Peripheral Frequency 26.613 6.653 0.832 0.208 0.013 (MHz) CLKREL 0000 0010 0101 0111...
- Page 18 AP08056 Power Saving Features Operating on a Lower Frequency Clock Mode Operating on a Lower Frequency Clock Mode The normal system clock runs in PLL Mode. The system frequency (f ) is defined as: ----------- - f ⋅ ⋅ The N factor is selected by the bitfield PLL_CON.NDIV. The P factor is fixed to 1. The K factor is fixed at 2 for XC866.
- Page 19 AP08056 Power Saving Features Operating on a Lower Frequency Clock Mode Device Clock in PLL Base Mode In the PLL base mode, the oscillator is disconnected from the PLL and the system frequency is derived from the VCO base (free running) frequency clock divided by the K factor: --- - f ⋅...
- Page 20 AP08056 Power Saving Features Operating on a Lower Frequency Clock Mode Table 12 are some results showing the current consumption by a XC866-1FR device, a XC866-4FR device and a XC886 device operating in PLL base mode. Table 12 Current consumption in PLL base mode XC866-1FR XC866-4FR XC886...
- Page 21 AP08056 Power Saving Features Operating on a Lower Frequency Clock Mode PLL_CON &= 0xF7;//Deselect VCO bypass mode //... device is running in PLL Mode Device Clock in Prescaler Mode In this mode, the system clock is derived from the oscillator clock divided by the P and K factor: ⋅...
- Page 22 AP08056 Power Saving Features Reset Current Reset Current This section will look at the current consumption by the devices in reset state, i.e. when the reset pin is held low. All the port pins are left floating except the reset pin which is grounded.
- Page 23 AP08056 Power Saving Features A Timer 2 Example A Timer 2 Example In this section, the XC866-4FR device and the XC888 device were configured to start timer 2 in auto-reload mode which generates an overflow in every 20 ms. The overflow will trigger an interrupt service routine that will toggle port 3.0.
- Page 24 AP08056 Power Saving Features A Timer 2 Example Table 16 Current consumed by XC866-4FR device when timer 2 is active = 79.84 MHz Current (mA) 0.052 1001 5.43 5.53 -0.10 0.026 1010 5.42 5.52 -0.10 0.013 1011 5.41 5.51 -0.10 1) Negative value indicates that slow-down-idle mode current >...
- Page 25 AP08056 Power Saving Features A Timer 2 Example Table 18 Current consumed by XC866-4FR device when timer 2 is active = 4.99 MHz Current (mA) Peripheral CLKREL Slow-Down Slow-Down- Difference Frequency (KHz) Idle (Y) X - Y 1663.33 0000 3.58 3.40 0.18 831.67...
- Page 26 AP08056 Power Saving Features Summary Summary • Idle mode, slow-down mode and power-down mode are the three power saving modes offered in the XC800 product family. • The combination of slow-down mode and idle mode may not necessarily consume less power as compared to slow-down mode alone. It will depend on factors such as the peripheral activities and the operating frequency.
- Page 27 AP08056 Power Saving Features Power Saving Checklist Power Saving Checklist • Disable the unused analog pins (Port 2) by setting them as output pins. • Input port pins should not be left floating. Floating port pins should enable pull-down or set as output port. Output pins that are pulled-up should be set to high. •...
- Page 28 . i n f i n e o n . c o m Published by Infineon Technologies AG...