XC800 Peripheral Highlights 8-bit microcontrollers July 2008 Industrial and Multimarket Microcontroller – AIM MC IMM Agenda Realtime Applications Example Switched Mode Power Supply – CC6 Example Current Measurement – CC6 & ADC Example Board Selftest – Ports Example Touchpad – CC6 & Ports June 2008 Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Page 2 Realtime Applications Realtime applications need: computing performance – this can be easily calculated guaranteed reaction time – this is difficult to guarantee Æ together this is called Realtime Performance How to get Realtime Performance use powerful MCU architectures (busses, datawidth, MUL/DIV pipeline...) ... this is quite expensive use good interrupt controllers ... 8051 has significant good interrupt performance use high clockspeed ... this is very expensive Æ fast memory, high current consumption etc... use intelligent peripherals ... this needs application knowhow and technical expertise June 2008 Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Page 3 CPU vs. Peripheral Performance Example: Servo Motor of a CNC Machine Crack on the cutter head Via Via CPU CPU Check Check limits limits every every 2µs 2µs Assumption: Assumption: 20 20 instructions instructions Additional Additional 10 10 MIPS MIPS CPU CPU performance performance needed needed for for aa “background” “background” task! task! June 2008 Via Via autonomous autonomous peripherals peripherals Check Check limits limits every every 2µs 2µs in in ADC ADC Trigger Trigger PWM PWM unit unit directly directly in in case case of of limit limit violation violation Zero Zero additional additional CPU CPU load load Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Page 4 Agenda Realtime Applications Example Switched Mode Power Supply – CC6 Example Current Measurement – CC6 & ADC Example Board Selftest – Ports Example Touchpad – CC6 & Ports June 2008 Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Page 5 Example Switched Mode Power Supply – CC6 for flyback converters, stepdown converters, PFC etc. a typical problem is that the switch control requires variable period and duty cycle a standard PWM module cannot do this – the signal is much too fast this is called critical conduction mode discontinuous mode etc... CC6 can solve this problem T13 in single shot mode start T13 on external event (T13HR) By this an aperiodic signal can be generated @ 100kHz (Ton + Toff ≠ contstant) June 2008 Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Page 6 Agenda Realtime Applications Example Switched Mode Power Supply – CC6 Example Current Measurement – CC6 & ADC Example Board Selftest – Ports Example Touchpad – CC6 & Ports June 2008 Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Page 7 Example Current Measurement – CC6 & ADC Single Shunt Current Measurement for SVM Controlled Motors ADC can be triggered by hardware „time-accurate“ T13 and T12 are synchronized by hardware ADC result is stored automatically decoupling of software and hardware Topology Space Vector Modulation (SVM) June 2008 Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Noisefree sampling (T13PM) Page 8 Agenda Realtime Applications Example Switched Mode Power Supply – CC6 Example Current Measurement – CC6 & ADC Example Board Selftest – Ports Example Touchpad – CC6 & Ports June 2008 Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Page 9 Example Board Selftest – Ports Using flexible port feature programmable pullup / pulldown strong pull with opendrain Short-Detection of two neighbour pins on boardlevel Emulation of external signals by pullup/down stimulation Æ external interrupts Æ external sensors, even analog Æ capture events etc. June 2008 short read pinlevel Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Page 10 Agenda Realtime Applications Example Switched Mode Power Supply – CC6 Example Current Measurement – CC6 & ADC Example Board Selftest – Ports Example Touchpad – CC6 & Ports June 2008 Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Page 11 Example Touchpad (1) A Touchpad is a capacitive switch without electro-mechanical parts with galvanic isolation finger It works like a RC oscillator where the C is changed by the „touching finger“ glass pad PCB to MCU portpin count oscillations over a certain time less oscillations when finger is on touchpad June 2008 Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Page 12 Example Touchpad (2) SW Solution – 100% CPU load start T2 T2 overflow T2 opendrain with pullup yes no pullup on read count no reset count pinlevel high CPU count above limit yes output low yes no ON OFF count++ June 2008 Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Page 13 Example Touchpad (3) HW Solution – zero CPU load T2 opendrain with pullup CC6 T2 ISR hardware start T0 read count count reset count above limit June 2008 yes no ON OFF Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Page 14 June 2008 Copyright © Infineon Technologies 2006. All rights reserved. AIM MC IMM Page 15