General Description
EM78P159N 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. 8 OPTION bits are also available to meet user’s requirements.

Features
■ Operating voltage range:
    • 2.1V~5.5V at 0°C~70°C
    • 2.3V~5.5V at 40°C~85°C
■ Operating frequency range (base on 2 clocks ):
    • Crystal mode: DC~20MHz at 5.0V, DC~8MHz at 3.0V, DC~4MHz at 2.1V
    • ERC mode: DC~4MHz at 5.0~2.1V
    • IRC mode: 4 choices of frequencies available; i.e., 8M, 4M, 1M, & 455kHz
■ IRC mode:
    • All these four main frequencies can be trimmed by programming with four calibrated bits in the ICE159N Simulator. OTP is auto trimmed by DWTR.
    • Temperature, Voltage, and Process changes will influence the frequency drift
    • Frequency deviation is only ±4.5% after auto trimming (based on Vdd=5V, Ta=25°C)
■ Fast set-up time only requires about 2ms in high XTAL and 32CLKS in IRC mode from wake up to operating mode
■ Low power consumption:
    • Less then 2mA at 5V/4MHz
    • Typically 20μA at 3V/32kHz
    • Typically 1μA 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
■ 8 programmable pull-down pins
■ 8 programmable open-drain pins
■ 2 programmable R-option pins
■ Package types:
    • 18 pin DIP 300mil : EM78P159NP
    • 18 pin SOP 300mil : EM78P159NM
    • 20 pin SSOP 209mil : EM78P159NAS
    • 20 pin SSOP 209mil : EM78P159NKM
■ 99.9% single instruction cycle commands
■ The transient point of system frequency between HXT and LXT is around 400kHz