Renesas Electronics Europe GmbH A © 2010 Renesas Electronics Corporation. All rights reserved. RL78 AD converter

© 2010 Renesas Electronics Corporation. All rights reserved. 2 Purpose This course provides an introduction to the RL78 AD converter. In detail the different modes and their usage are explained. Objective Learn about the RL78 AD converter and its capabilities. Content 28 pages (including this page) x questions Learning Time 20 minutes Introduction

© 2010 Renesas Electronics Corporation. All rights reserved. 3 ADC overview The AD converter of the RL78 products is using the SAR method Depending on the device there different numbers of input channels available

© 2010 Renesas Electronics Corporation. All rights reserved. 4 Block Diagram Peripherals – A/D Converter

© 2010 Renesas Electronics Corporation. All rights reserved. 5 Features 10-bit A/D Conversion –Channel selection from 6 to 26 channels –Each time an A/D conversion operation ends, an interrupt request (INTAD) is generated –Several modes available –select-mode/scan-mode –hard (timer)- / software triggered –single (one shot) and sequential –Internal voltage reference –Internal temperature sensor –Unused A/D Inputs can be set as I/O ports –Programmable limits to release snooze mode –The A/D Converter registers can be accessed by DMA –Diagnostics A/D Converter

© 2010 Renesas Electronics Corporation. All rights reserved. 6 A/D Converter specification Conversion time down to 2.2us (selectable) Operating voltage range –AVref ≤ VDD = 1.6V to 5.5V Internal reference 1,44V –Can be used as reference or input voltage Integrated temperature sensor A/D Converter

© 2010 Renesas Electronics Corporation. All rights reserved. 7 Conversion modes One shot conversion mode Sequential conversion mode Channel selection Select mode Scan mode conversion stopconversionconversion stop triggerinterrupt conversion stop conversion triggerinterrupt stop conversion stop Ch 0 Ch n Ch 1 Ch 0 Ch n Ch 1 AD converter Operating modes

© 2010 Renesas Electronics Corporation. All rights reserved. 8 AD converter Operating modes (cont.) Trigger sources Software trigger Hardware trigger –Timer Array Unit –Interval timer –RTC

© 2010 Renesas Electronics Corporation. All rights reserved. 9 AD converter Operation modes (cont.) AD converter window function End of conversion interrupt is generated only in case –AD result inside valid range –AD result outside valid range Valid range can be specified by ADUL and ADLL (8 bit res.)

© 2010 Renesas Electronics Corporation. All rights reserved. 10 AD converter with external trigger Delayed AD converter start Background operation, no CPU usage Ext. interrupt starts timer Timer overflow starts AD converter

© 2010 Renesas Electronics Corporation. All rights reserved. 11 AD converter with DMA DMA can be used for a background saving of AD results in SCAN mode.

© 2010 Renesas Electronics Corporation. All rights reserved. 12 STOP ADC with trigger by timer ACTIVE ADC Value in range Lower Limit ADC Values out of Range: Wake up the CPU and Process the results ADC operation during standby state Four comparison criteria: Within/Outside Window, Higher/Lower than Limit Over 60% reduction in power consumption vs. to standard ADC operation ADC Data Active mode STOP modeSnoozeSTOP modeSnooze Active mode ADC Data Data Match Upper Limit SNOOZE Values in Range Process Data Yes No STOP mode 0.52uA STOP mode 0.52uA ~800uA + 0.8mA if ADC Enabled Time Analog input Over 60% Reduction in Power Consumption Over 60% Reduction in Power Consumption Timer Trigger No Data Match AD converter with Snooze Mode

© 2010 Renesas Electronics Corporation. All rights reserved. 13 AD converter Diagnostics Test of the sample and hold circuit by switching the internal references against Vdd and GND.

© 2010 Renesas Electronics Corporation. All rights reserved. 14 Summary RL78 AD converter Modes of operation Capabilities Diagnostic Function Thank You For more information on RL78 devices, visit:

Renesas Electronics Europe © 2010 Renesas Electronics Corporation. All rights reserved. Thank You