Functional Description
µPD7894xx
8-Bit Microcontrollers with LCD
Serial Interface
Timer
Clock Generator
Interrupt controller
Comparator
All devices have a serial interface that can be operated in asynchronous serial interface
(UART) mode or in three-wire clocked serial interface (CSI) mode via a dedicated baud
rate generator. In addition, the baud rate can be defined by scaling the input clock. The
UART also features full-duplex operation. In CSI mode, an 8-bit data transfer executes via
three lines supporting simultaneous transmit and receive operations to reduce data
transfer processing time.
The devices have two 8-bit timer/event counters, one 8-bit and one 16-bit timer, as well as
a watchdog timer. The timers can be used as interval timers and external event counters,
or to generate square waves of arbitrary frequency. The watchdog timer has interval timer
functions, generates non-maskable or maskable interrupts, and is used to detect inadvert-
ent program loops.
The clock generator provides the operating frequency supplied to the CPU and peripheral
hardware and requires an external crystal (1 to 5 MHz). The system clock, controlled by
the processor clock control (PCC) register, uses this source to generate the internal
operating frequency. Optionally the operating frequency also can be prescaled. Executing
the Stop instruction stops oscillation. For power-saving purposes, the devices have a
subsystem clock operating at 32.768 kHz.
The interrupt controller handles various interrupt requests issued by internal peripheral
hardware or external devices. Four external and 12 internal interrupts are incorporated as
maskable interrupts, with a priority of 0 to 7.
The comparator compares an input voltage with the reference voltage. The result can be
read using memory manipulation instruction.
Ordering Information
Power-Saving Features: Normal, Halt and Stop Modes
Modes and Typical Power at 5 MHz
Normal Mode:
Chip 100% On
Halt Mode:
CPU Clock Off
Stop Mode: Main Clock Off
Voltage
5 V
2 V
Main and
clocks On
28 mW
0.8 mW
subsystem
Main and
clocks On
6.0 mW
0.6 mW
subsystem
32 kHz
clock On
0.13 mW
0.005 mW
subsystem
32 kHz subsystem clock
not used
0.0005 mW
0.0001 mW
Documentation
µPD7894xx
8-Bit Microcontrollers with LCD
Document
U11047E
U12358E
Number
J2V0UM00
J1V0UM00*
Device
K0S
µPD7894xx
Type
Instruction Manual
User’ s Manual
* Preliminary document
U12240EJ1V0PM00*
U12302EJ1V0PM00*
U12321EJ1V0PM00*
µP
µP
D78940x
D78941x
µPD78F9418
Data Sheet
Data Sheet
Data Sheet
Ordering Information
µ
PD78940x
µPD78941x
Part Number
Internal ROM
8-Bit A/D
Part
Number
Internal ROM
10-Bit A/D
µPD789405GC/GK
µPD789406GC/GK
µPD789407GC/GK
12 KB mask ROM
16 KB mask ROM
24 KB mask ROM
7
7
7
channels
channels
channels
µPD789415GC/GK
µPD789416GC/GK
µPD789417GC/GK
µPD78F9418GC/GK
12 KB mask ROM
16 KB mask ROM
24 KB mask ROM
32 KB mask ROM
7
7
7
7
channels
channels
channels
channels
The information in this document is current as of February 2002. 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 suppor t a given application.
(Note) (1) "NEC" as used in this statement means NEC Corporation and also includes its majority-owned subsidiaries.
(2) "NEC semiconductor products" means any semiconductor product developed or manufactured by or for NEC (as defined above). |
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