EM78P157N
8-Bit Microcontroller with OTP ROM
1 General Description
EM78P157N is an 8-bit microprocessor designed and developed with low-power,
high-speed CMOS technology. It is equipped with 1K*13-bits Electrical One Time
Programmable Read Only Memory (OTP-ROM). It provides three PROTECTION bits
to prevent user’s code in the OTP memory from being intruded. Eight OPTION bits are
also provided to meet user’s additional requirements.
With its OTP-ROM feature, the EM78P157N is able to offer a convenient way of
developing and verifying user’s programs. Moreover, user can take advantage of
ELAN DWriter to easily program his development code.
2 Features
Operating voltage range: 2.5V~5.5V
Operating temperature range: -40°C~85°C
Operating frequency range (base on 2 clocks ):
• Crystal mode: DC~20MHz at 5V, DC~8MHz at 3V, DC~4MHz at 2.5V.
• ERC mode: DC~4MHz at 5V, DC~4MHz at 3V, DC~4MHz at 2.5V.
Low power consumption:
• Less then 2 mA at 5V/4MHz
• Typically 20 µA at 3V/32KHz
• Typically 1 µA during sleep mode
1K × 13 bits on chip ROM
One security register to prevent intrusion of OTP memory codes
One configuration register to accommodate user’s requirements
48× 8 bits on chip registers (SRAM, general purpose register)
2 bi-directional I/O ports
5 level stacks for subroutine nesting
8-bit real time clock/counter (TCC) with selective signal sources, trigger edges, and
overflow interrupt
Two clocks per instruction cycle
Power down (SLEEP) mode
Three available interruptions
• TCC overflow interrupt
• Input-port status changed interrupt (wake up from sleep mode)
• External interrupt
Product Specification (V1.0) 09.22.2005
•1
(This specification is subject to change without further notice)