MOS INTEGRATED CIRCUIT
4-BIT SINGLE-CHIP MICROCOMPUTER
The µPD7554A is a product of the µPD7554, 7564 sub-series which is a 4-bit single-chip microcomputer with a
small number of ports in a small package, which is enabled to operate even at the super-low voltage of 2.0 V so
that it is optimized for handy-type systems operating with dry cells. The µPD7554A is a low-order model in the
µPD7500 series (µPD7554A only).
This device incorporates a serial interface, and serves as the sub-CPU for a high-order model of that series or
the 8-bit microcomputer. It is optimized for distributed processing of the system.
The µPD7554A has outputs to directly drive a triac and LEDs and allows selection among many types of input/
output circuits using their respective mask options, sharply reducing the number of external circuits required.
Details of functions are described in the User’s Manual shown below. Be sure to read in design.
µPD7554, 7564 User’s Manual: IEM-1111D
• Range of supply voltage 7554A : 2.0 to 6.0 V
7554A(A) : 2.7 to 6.0 V
• Drive with two 1.5 V manganese cells
• 47 types of instructions
(Subset of µPD7500H SET B)
• Instruction cycle
External clock : 2.86 µs (in operation at 700 kHz, 5 V)
RC oscillation : 4 µs (in operation at 500 kHz, 5 V)
• Program memory (ROM) capacity: 1024 × 8 bits
• Data memory (RAM) capacity: 64 × 4 bits
• Test source: One external source and two internal
• 8-bit timer/event counter
• 16 I/O lines (Total output current of all pins: 100 mA)
• Can directly drive a triac and a LED: P80 to P83
• Can directly drive LEDs: P100 to P103 and P110
• Mask option function provided for every port
• 8-bit serial interface
• Standby (STOP/HALT) function
• Low supply voltage data retaining function for data
• Built-in ceramic oscillator for system clock RC
Oscillation with an external resistor R (Incorporat-
ing capacitor C)
µPD7554A : Sub-CPU including handy-type system, PPC, printer, VCR, audio equipments, etc.
µPD7554A(A) : Automotive and transportation equipments, etc.
The quality level and absolute maximum ratings of the µPD7554A and the µPD7554A(A) differ.
Except where specifically noted, explanations here concern the µPD7554A as a representative product.
If you are using the µPD7554A(A), use the information presented here after checking the functional differences.
Document No. IC-2419C
(O. D. No. IC-7835C)
Date Published January 1995 P
Printed in Japan
The information in this document is subject to change without notice.
The mark 5 shows major revised points.