MicroConverter , Dual-Channel a 16-/24-Bit ADCs with Embedded FLASH MCU ADuC824 FEATURES FUNCTIONAL BLOCK DIAGRAM High Resolution Sigma-Delta ADCs Two Independent ADCs (16- and 24-Bit Resolution) AVDD AVDD ADuC824 Programmable Gain Front End AIN1 24-Bit No Missing Codes, Primary ADC PRIMARY AIN2 PGA BUF MUX 24-BIT - ADC 13-Bit p-p Resolution 20 Hz, 20 mV Range CURRENT IEXC1 SOURCE 18-Bit p-p Resolution 20 Hz, 2.56 V Range IEXC2 MUX AGND Memory AIN3 12-BIT AIN4 AUXILIARY 8 KB On-Chip Flash/EE Program Memory MUX VOLTAGE O/P DAC BUF 16-BIT - ADC AIN5 DAC 640 Bytes On-Chip Flash/EE Data Memory Flash/EE, 100 Year Retention, 100 Kcycles Endurance 8051-BASED MCU WITH ADDITIONAL TEMP PERIPHERALS SENSOR 256 Bytes On-Chip Data RAM 8 KBYTES FLASH/EE PROGRAM MEMORY 640 BYTES FLASH/EE DATA MEMORY 8051-Based Core INTERNAL PROG. 256 BYTES USER RAM BANDGAP 8051-Compatible Instruction Set (12.58 MHz Max) CLOCK 3 16 BIT ON-CHIP MONITORS VREF DIVIDER TIMER/COUNTERS POWER SUPPLY 32 kHz External Crystal, On-Chip Programmable PLL 1 TIME INTERVAL MONITOR Three 16-Bit Timer/Counters COUNTER WATCHDOG TIMER EXTERNAL OSC 2 26 Programmable I/O Lines I C-COMPATIBLE VREF AND 4 PARALLEL UART AND SPI DETECT PLL PORTS 11 Interrupt Sources, Two Priority Levels SERIAL I/O Power REFIN REFIN+ XTAL1 XTAL2 Specified for 3 V and 5 V Operation Normal: 3 mA 3 V (Core CLK = 1.5 MHz) Power-Down: 20 A (32 kHz Crystal Running) low-level signals). The ADCs with on-chip digital filtering are On-Chip Peripherals intended for the measurement of wide dynamic range, low-frequency On-Chip Temperature Sensor signals, such as those in weigh scale, strain-gauge, pressure trans- 12-Bit Voltage Output DAC ducer, or temperature measurement applications. The ADC output Dual Excitation Current Sources data rates are programmable and the ADC output resolution will Reference Detect Circuit vary with the programmed gain and output rate. Time Interval Counter (TIC) The device operates from a 32 kHz crystal with an on-chip PLL UART Serial I/O 2 generating a high-frequency clock of 12.58 MHz. This clock is, I C -Compatible and SPI Serial I/O in turn, routed through a programmable clock divider from Watchdog Timer (WDT), Power Supply Monitor (PSM) which the MCU core clock operating frequency is generated. The APPLICATIONS microcontroller core is an 8052 and therefore 8051-instruction- Intelligent Sensors (IEEE1451.2-Compatible) set-compatible. The microcontroller core machine cycle consists Weigh Scales of 12 core clock periods of the selected core operating frequency. Portable Instrumentation 8 Kbytes of nonvolatile Flash/EE program memory are provided Pressure Transducers on-chip. 640 bytes of nonvolatile Flash/EE data memory and 420 mA Transmitters 256 bytes RAM are also integrated on-chip. The ADuC824 also incorporates additional analog functionality GENERAL DESCRIPTION with a 12-bit DAC, current sources, power supply monitor, The ADuC824 is a complete smart transducer front-end, inte- and a bandgap reference. On-chip digital peripherals include a grating two high-resolution sigma delta ADCs, an 8-bit MCU, watchdog timer, time interval counter, three timers/counters, 2 and program/data Flash/EE Memory on a single chip. This low and three serial I/O ports (SPI, UART, and I C-compatible). power device accepts low-level signals directly from a transducer. On-chip factory firmware supports in-circuit serial download and The two independent ADCs (Primary and Auxiliary) include a debug modes (via UART), as well as single-pin emulation mode temperature sensor and a PGA (allowing direct measurement of via the EA pin. A functional block diagram of the ADuC824 is shown above with a more detailed block diagram shown in MicroConverter is a registered trademark of Analog Devices, Inc. Figure 12. SPI is a registered trademark of Motorola, Inc. 2 The part operates from a single 3 V or 5 V supply. When operating I C is a registered trademark of Philips Semiconductors, Inc. from 3 V supplies, the power dissipation for the part is below 10 mW. The ADuC824 is housed in a 52-lead MQFP package. REV.B Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. use, nor for any infringements of patents or other rights of third parties that Tel: 781/329-4700 www.analog.com may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781/326-8703 Analog Devices, Inc., 2002ADuC824 TABLE OF CONTENTS FEATURES.......................................................................... 1 NONVOLATILE FLASH/EE MEMORY ........................... 37 GENERAL DESCRIPTION................................................. 1 Flash/EE Memory Overview............................................. 37 SPECIFICATIONS .............................................................. 3 Flash/EE Memory and the ADuC824............................... 37 TIMING SPECIFICATIONS .............................................. 8 ADuC824 Flash/EE Memory Reliability........................... 37 ABSOLUTE MAXIMUM RATINGS................................. 18 Using the Flash/EE Program Memory .............................. 38 PIN CONFIGURATION .................................................... 18 Flash/EE Program Memory Security ................................ 39 ORDERING GUIDE.......................................................... 18 Using the Flash/EE Data Memory .................................... 39 PIN FUNCTION DESCRIPTIONS................................... 19 USER INTERFACE TO OTHER ON-CHIP ADuC824 ADuC824 BLOCK DIAGRAM .......................................... 21 PERIPHERALS .............................................................. 41 MEMORY ORGANIZATION............................................ 22 DAC................................................................................ 41 OVERVIEW OF MCU-RELATED SFRS........................... 23 On-Chip PLL .................................................................. 42 Accumulator (ACC) ........................................................ 23 Time Interval Counter (TIC) ........................................... 43 B SFR (B) ....................................................................... 23 Watchdog Timer.............................................................. 46 Stack Pointer (SP) ........................................................... 23 Power Supply Monitor ..................................................... 47 Data Pointer (DPTR) ...................................................... 23 Serial Peripheral Interface ................................................ 48 2 Program Status Word (PSW) ........................................... 23 I C-Compatible Interface ................................................. 50 Power Control (PCON) ................................................... 23 8051-COMPATIBLE ON-CHIP PERIPHERALS .............. 51 SPECIAL FUNCTION REGISTERS................................. 24 Parallel I/O Ports 03 ....................................................... 51 SFR INTERFACE TO THE PRIMARY AND Timers/Counters .............................................................. 51 AUXILIARY ADCs ......................................................... 25 TIMER/COUNTER 0 AND 1 OPERATING MODES ...... 54 ADCSTAT ...................................................................... 25 UART Serial Interface ..................................................... 57 ADCMODE .................................................................... 26 Interrupt System .............................................................. 60 ADC0CON ..................................................................... 27 ADuC824 HARDWARE DESIGN CONSIDERATIONS... 62 ADC1CON ..................................................................... 28 Clock Oscillator ............................................................... 62 SF ................................................................................... 28 External Memory Interface............................................... 62 ICON .............................................................................. 29 Power-On Reset Operation .............................................. 63 ADC0H/ADC0M/ADC0L ............................................... 29 Power Supplies ................................................................ 63 ADC1H/ADC1L ............................................................. 29 Power Consumption ........................................................ 64 OF0H/OF0M/OF0L ........................................................ 30 Power-Saving Modes ....................................................... 64 OF1H/OF1L ................................................................... 30 Grounding and Board Layout Recommendations ............. 64 GN0H/GN0M/GN0L ...................................................... 30 ADuC824 System Self-Identification................................ 65 GN1H/GN1L .................................................................. 30 OTHER HARDWARE CONSIDERATIONS..................... 65 PRIMARY AND AUXILIARY ADC DESCRIPTION........ 31 In-Circuit Serial Download Access ................................... 65 Overview ......................................................................... 31 Embedded Serial Port Debugger ...................................... 65 Primary ADC .................................................................. 31 Single-Pin Emulation Mode ............................................. 65 Auxiliary ADC ................................................................. 32 Enhanced-Hooks Emulation Mode .................................. 66 PRIMARY AND AUXILIARY ADC NOISE Typical System Configuration .......................................... 66 PERFORMANCE ............................................................ 33 QUICKSTART DEVELOPMENT SYSTEM..................... 67 Analog Input Channels .................................................... 33 OUTLINE DIMENSIONS ................................................. 68 Primary and Auxiliary ADC Inputs .................................. 33 Revision History .................................................................. 68 Analog Input Ranges........................................................ 33 Programmable Gain Amplifier.......................................... 34 Bipolar/Unipolar Inputs ................................................... 34 Burnout Currents............................................................. 34 Excitation Currents.......................................................... 35 Reference Input ............................................................... 35 Reference Detect ............................................................. 35 Sigma-Delta Modulator ................................................... 35 Digital Filter .................................................................... 35 ADC Chopping ............................................................... 36 Calibration ...................................................................... 37 REV. B 2