Epson Arm S1C31 Series Technical Manual

19 12-BIT A/D CONVERTER (ADC12A)S1C31D41 TECHNICAL MANUAL Seiko Epson Corporation 19-1(Rev. 1.1)19 12-bit A/D Converter (ADC12A)19.1 OverviewThe ADC12A is a successive approximation type 12-bit A/D converter.The features of the ADC12A are listed below.• Conversion method: Successive approximation type• Resolution: 12 bits• Analog input voltage range: Reference voltage VREFA to VSS• Supports two conversion modes: 1. One-time conversion mode2. Continuous conversion mode• Supports three conversion triggers: 1. Software trigger2. 16-bit timer underflow trigger3. External trigger• Can convert multiple analog input signals sequentially.• Can generate conversion completion and overwrite error interrupts.• Can issue a DMA transfer request when a conversion has completed.Figure 19.1.1 shows the ADC12A configuration.Table 19.1.1 ADC12A Configuration of S1C31D41Item 32-pin package 48-pin package 64-pin packageNumber of channels 1 channel (Ch.0)Number of analog signal inputs per channel Ch.0: 6 inputs(ADIN00–04, 07 *1)Ch.0: 8 inputs(ADIN00–07 *1)16-bit timer used as conversion clock andtrigger sourcesCh.0 ← 16-bit timer Ch.7VREFA pin (reference voltage input) Can be input externally or generated internally *2*1 ADIN07 is connected to the temperature sensor output.*2 The reference voltage generator output can be input as the reference voltage.For more information, refer to the “Temperature Sensor/Reference Voltage Generator” chapter.ADC12A Ch.nTriggerselect circuitSuccessiveapproximationcontrol circuitCNVTRG[1:0]CNVMDMODENADSTSTMDAD0D[15:0]ADSTAT[2:0]BSYSTATSMPCLK[2:0]VRANGE[1:0]#ADTRGnADINn0ADINn1ADINnmVREFAnInterruptcontrolcircuitAD0CIFAD1CIFADmCIFOVIFAD0CIEAD1CIEADmCIEOVIECPUDMAcontrollerDMA requestcontrol circuit ADCDMAENxInternal data busTimer16-bit timerCh.kUnderflowClockgeneratorCLK_T16_kMUX+–Comparator withsample & hold circuitD/AconverterFigure 19.1.1 ADC12A ConfigurationNote: In this chapter, n, m, and k refer to an ADC12A channel number, an analog input pin number, anda 16-bit timer channel number, respectively.