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.

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

● Programmable free running watchdog timer

● 8 programmable pull-high pins

● 7 programmable pull-down pins

● 8 programmable open-drain pins

● 2 programmable R-option pins

● Package types:

? 14 pin DIP 300mil : EM78P157NBP

? 14 pin SOP 150mil : EM78P157NBM

? 18 pin DIP 300mil : EM78P157NAP

? 18 pin SOP 300mil : EM78P157NAM

? 20 pin SSOP 209mil : EM78P157NAAS

? 20 pin SSOP 209mil : EM78P157NAKM

● 99.9 single instruction cycle commands

● The transient point of system frequency between HXT and LXT is around 400KHz