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© 2009, Renesas Technology America, Inc., All Rights Reserved 1 Course Introduction Purpose: This course provides an overview of the serial communication interfaces and data converters on devices in the SH-2 and SH-2A families of 32-bit RISC microcontrollers, which are members of the SuperH ™ series Objectives: Gain a basic knowledge of the features and operation of the serial communication interface (SCI) Discover the extra capabilities of the SCIF version Learn about synchronous serial interface options Learn basic facts about analog-to-digital converter (ADC or A/D) and digital-to-analog converter (DAC or D/A) peripherals Content: 22 pages 3 questions Learning Time: 20 minutes
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© 2009, Renesas Technology America, Inc., All Rights Reserved SuperH Peripheral Functions Microcontrollers for embedded system applications require extensive on-chip peripherals to Minimize system chip count Reduce overall system cost Facilitate small system size, etc. Built-in peripheral functions must Provide required capabilities Deliver needed performance levels Offer design flexibility Maintain a basic commonality within product family, if possible Offer an acceptable cost-benefit compromise, etc. SH-2 SuperH 32-bit RISC CPU SH7047 SuperH Series Microcontroller Multi-function Timer Pulse Unit Compare-Match Timer Watchdog Timer Advanced User Debugger Bus Interface Flash Bus State Controller High-performance User Debug Interface Clock Pulse Generator RAM Data Transfer Controller Interrupt Controller User Break Controller I/O Ports Motor Management Timer Serial Communication Interface D/A Converter* A/D Converter * included on some SH-2 series devices, but not the SH7047 CAN Function
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© 2009, Renesas Technology America, Inc., All Rights Reserved 3 Serial Communication Interface SuperH-series devices feature two types of serial communication interface: SCI on first-generation devices Serial communication interface with FIFO (SCIF) as well on SH-2A microcontrollers and newer SH-2 devices 16-stage FIFO Makes it possible to transmit and receive data on each channel for high-speed communication SCI and SCIF support asynchronous and clocked synchronous serial communication SCIF
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© 2009, Renesas Technology America, Inc., All Rights Reserved 4 Serial Communication Modes Asynchronous mode provides 7- or 8-bit data length 1 or 2 stop bits Even, odd, or no parity Parity, framing and overrun error detection Break detection (SH-2A) Up to 3Mbit/s operation Clocked synchronous mode provides 8-bit data length Overrun error detection Up to 5Mbit/s operation Data format in clocked synchronous mode Data format in asynchronous mode
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© 2009, Renesas Technology America, Inc., All Rights Reserved 5 Full Duplex Communication SCI and SCIF offer full duplex communication, allowing simultaneous transmission and reception Each channel has an Independent baud rate generator that uses none of the microcontroller’s timer resources The interface supports internal and external clock sources
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© 2009, Renesas Technology America, Inc., All Rights Reserved 6 Baud Rate/Bit Error Calculation When you choose a baud rate, consider the percentage error rate, too!
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© 2009, Renesas Technology America, Inc., All Rights Reserved 7 Four sources can trigger interrupts: Tx (FIFO) data empty Rx (FIFO) data full Receive error Break condition (SH-2A) If a receive error occurs, it must be cleared before reception can continue With FIFO you can Ascertain the quantity of Tx and Rx FIFO data in the buffers Keep track of the number of Rx errors SCIF can generate a timeout (DR) error in asynchronous mode Rx and Tx interrupts can activate DMAC and DTC transfers SCI and SCIF can be put into standby mode to conserve power Generating Interrupts (Automatically enables)
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© 2009, Renesas Technology America, Inc., All Rights Reserved 8 Modem Flow Control SCIF in SH-2A devices can generate modem control signals (/CTS, /RTS)
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© 2009, Renesas Technology America, Inc., All Rights Reserved 10 I 2 C Interface and Peripherals I 2 C is a serial bus interface standard developed by Philips Semiconductor Two SH-2 series I 2 C peripherals provide an I 2 C-compatible bus interface IIC2 on earlier devices in the SH-2 series IIC3 on SH-2A microcontrollers and newer SH-2 devices Select I 2 C or clocked-synchronous serial formats Master and slave modes are supported Independent registers make possible continuous data transmission and reception Shift register Tx data register Rx data register Peripherals operate in I 2 C or clocked synchronous mode
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© 2009, Renesas Technology America, Inc., All Rights Reserved 11 I 2 C Bus Format Features IIC2 and IIC3 peripherals can Automatically generate start and stop conditions Automatically transmit acknowledge bit Reception acknowledge levels are selectable IIC3 (on SH-2A and newer SH-2 devices) has a bit synchronization/wait function in master mode that Monitors SCL per bit Synchronizes timing automatically Holds SCL low to wait Multiple interrupt sources include Tx empty, Tx end, Rx data full, arbitration lost, NACK detection, and stop condition detection Tx data empty or Rx data full can activate SH-2A DMAC Direct bus drive is provided
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© 2009, Renesas Technology America, Inc., All Rights Reserved 12 Clocked Synchronous Serial This format Adds more synchronous serial communication channels Supports multiple interrupt sources, including Tx data empty, Tx end, Rx data full, and overrun error Tx data empty and Rx data full interrupts can activate DMAC interrupt handling on SH-2A series microcontrollers SDA outputs data in synchronization with the SCL clock Bit 0 Bit 7 SDA SCL Bit 6Bit 5Bit 4Bit 3Bit 2Bit 1
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© 2009, Renesas Technology America, Inc., All Rights Reserved 13 IIC3: I 2 C Interface on SH-2A MCU IIC3 Implementation IIC3 External Circuit Connections
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© 2009, Renesas Technology America, Inc., All Rights Reserved 14 Synchronous Serial Comm. Unit SSU on the SH-2 series devices Communicates with clocked synchronous devices that use separate input and output pins Works in standard clocked synchronous mode Supports master and slave modes of operation with internal or external clock Has selectable clock polarity and phase Supports full duplex communication with 8-, 16-, and 32-bit-wide data Can be configured to send LSB or MSB first Provides interrupt sources: Tx end, Tx empty, Rx full, overrun, and conflict errors Triggers DTC for interrupt handling Can be put into standby mode to conserve power
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© 2009, Renesas Technology America, Inc., All Rights Reserved 16 Analog-to-Digital Converter This peripheral Converts analog voltages to numerical values Uses successive approximation with up to 12-bit resolution Supports up to 16 input channels Devices with 2 or 3 ADCs can make simultaneous conversions on multiple channels Latest analog-to-digital converters offer As little as 1 s conversion time Individual channels with their own 16-bit result register Several operating modes are available: Single Multi (conversion on 1 – 4 or 1 – 8 channels) Scan (continuous conversion on 1 – 4 or 1 – 8 channels)
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© 2009, Renesas Technology America, Inc., All Rights Reserved 17 ADC Features Sample-and-hold function Samples input signal voltage Holds voltage constant during conversion process Conversion start methods Software MTU, MTU2, or MTU2S trigger (MTU2S on SH-2A devices) External trigger input Interrupt generated on completion of A/D conversion DMAC or DTC transfer triggered on end of conversion Module standby mode to save power
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© 2009, Renesas Technology America, Inc., All Rights Reserved 18 ADC Implementation
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© 2009, Renesas Technology America, Inc., All Rights Reserved 19 ADC Conversion Errors
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© 2009, Renesas Technology America, Inc., All Rights Reserved 20 Digital-to- Analog Converter Features include 2 output channels 8-bit resolution 10 s conversion time (20pF load) Output voltage 0V to AVref DAC holds output voltage constant, even in software standby mode DAC can be put in module standby mode to conserve power DACR: D/A Control Register DADR0: D/A Data Register 0; DADR1: D/A Data Register 1 8-bit D/A DACRDACR Bus Interface Module Data Bus Internal Data Bus AVCC AVSS DADR0DADR0 Control Circuit DADR1DADR1 DA0 DA1 AVref
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© 2009, Renesas Technology America, Inc., All Rights Reserved 22 Course Summary Serial communication interfaces Analog-to-Digital converter Digital-to-Analog converter
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