block diagram k0s f amily ?d78988 1 ultra-low-power 8-bit microcontroller with lcd controller the ?d789881 is ideal for-battery-powered applications as it was designed for ultra-low power consumption of 18 a at 2.7 volts during normal operation and 0.9 ? in stop mode. it also has an lcd controller that can directly drive 104 lcd segments. a built-in 500 khz on-chip oscillator drives the cpu clock, while all peripherals operate from an external 32 khz clock. users can dynamically switch between the two clock speeds to accomodate the performance and power consumption requirements for their applications. the product s extensive tool chain contains a software simulator, c compiler, relocatable assembler, debugger, and in-circuit emulator. programming examples for the on-chip peripherals can be found in the microcontroller section of www.necel.com. 18 a operating current consumption 0.9 ? standby current consumption 26x4 lcd controller/driver 32 kb flash and 16 kb rom versions 512 kb sram peripherals operating from external 32 khz clock 500 khz internally generated cpu clock 4 s instruction execution time (min.) hardware multiplier bit manipulation instructions description features serial uart interface 8-bit timer/counter 16-bit counter/timer watchdog timer real-time clock up to 28 i/o pins interrupt controller standby control (halt, stop modes) power supply voltage: 2.7-3.5 v operating temperature: -40 to +85 c 64-pin qfp (10 x 10 mm)
power-saving modes to maximize power savings, the pd789881 has a stop mode in which all functions are shut down except for timer 51. in this mode, the device draws less than 0.9 ?. timer 51 can be used as a very flexible real-time clock that can be dynamically modified by the user. timer 51 (figure 1) can have either an internal clock input or an external clock input. if a clock input is selected, the input frequency can be selected by the value specified in a special function register. the available input frequencies were carefully chosen to provide extensive timing capabilities. for example, if the f xt /2 12 clock input is selected, it provides a signal to the timer register (tm51) every 0.125 seconds. if the 8-bit compare register (cr51) is set with a value of 8, then the device wakes up every 1 second. altering the compare register value yields wake-up times between 0.125 and 32 seconds. this flexibility comes from using only one of the seven different clock inputs. block diagram figure 1: 8-bit timer/event counter 51 01rc-0156b (11/01)
power-saving modes voltage modes and typical current at 500 khz normal mode: chip 100% on halt mode: cpu clock off stop mode main and subsytem clocks on main and subsytem clocks on 32 khz subsystem clock on 3.0 v 21 a 6 a 0.9 ? 2.7 v 18 a 5 a 0.9 ? ?d78988 1 ultra-low-power 8-bit microcontroller with lcd controller ordering information part number internal rom ?d789881gb-xxx-8eu 16 kb mask rom ?d78f9882gb-8eu 32 kb flash rom
the information in this document is current as of december, 2001. the information is subject to change without notice. for actual design-in, refer to the latest publications of nec's data sheets or data books, etc., for the most up-to-date specifications of nec semiconductor products. not all products and/or types are available in every country. please check with an nec sales representative for availability and additional information. no part of this document may be copied or reproduced in any form or by any means without prior written consent of nec. nec assumes no responsibility for any errors that may appear in this document. nec does not assume any liability for infringement of patents, copyrights or other intellectual property rights of third parties by or arising from the use of nec semiconductor products listed in this document or any other liability arising from the use of such products. no license, express, implied or otherwise, is granted under any patents, copyrights or other intellectual property rights of nec or others. descriptions of circuits, software and other related information in this document are provided for illustrative purposes in semiconductor product operation and application examples. the incorporation of these circuits, software and information in the design of customer's equipment shall be done under the full responsibility of customer. nec assumes no responsibility for any losses incurred by customers or third parties arising from the use of these circuits, software and information. while nec endeavours to enhance the quality, reliability and safety of nec semiconductor products, customers agree and acknowledge that the possibility of defects thereof cannot be eliminated entirely. to minimize risks of damage to property or injury (including death) to persons arising from defects in nec semiconductor products, customers must incorporate sufficient safety measures in their design, such as redundancy, fire-containment and anti-failure features. nec semiconductor products are classified into the following three quality grades: standard , special and specific . the "specific" quality grade applies only to semiconductor products developed based on a customer-designated quality assurance program for a specific application. the recommended applications of a semiconductor product depend on its quality grade, as indicated below. customers must check the quality grade of each semiconductor product before using it in a particular application. "standard": computers, office equipment, communications equipment, test and measurement equipment, audio and visual equipment, home electronic appliances, machine tools, personal electronic equipment and industrial robots. "special": transportation equipment (automobiles, trains, ships, etc.), traffic control systems, anti-disaster systems, anti-crime systems, safety equipment and medical equipment (not specifically designed for life support). "specific": aircraft, aerospace equipment, submersible repeaters, nuclear reactor control systems, life support systems and medical equipment for life support, etc. the quality grade of nec semiconductor products is standard unless otherwise expressly specified in nec's data sheets or data books, etc. if customers wish to use nec semiconductor products in applications not intended by nec, they must contact an nec sales representative in advance to determine nec's willingness to support a given application. (note) (1 ) "nec" as used in this statemen t means nec corporatio n an d also in clu des its majori ty-own ed subsidiari es. (2) "nec semi co nductor products" mea ns a ny semic on ductor product devel oped or man ufac tured by or for n ec (a s define d above ). to find out more about the products and services available from nec electronics, call 1-800-366-9782, fax 1-800-729-9288, or visit our web site at www.necel.com printed in u.s.a. document no. 50935 ?d78988 1 ultra-low-power 8-bit microcontroller with lcd controller
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