GENERAL DESCRIPTION

EM78P156EH is an 8-bit microprocessor designed and developed with low-power and high-speed CMOS technology. It is equipped with 1K*13-bits Electrical One Time Programmable Read Only Memory (OTP-ROM). It provides a PROTECTION bit to prevent user’s code in the OTP memory from being intruded. 6 OPTION bits are also available to meet user’s requirements. With its OTP-ROM feature, the EM78P156EH is able to offer a convenient way of developing and verifying user’s programs. Moreover, user can take advantage of EMC Writer to easily program his development code.

FEATURES

? Operating voltage range : 3.2V~5.5V

? Operating temperature range: 0°C~70°C

? Operating frequency rang (base on 2 clocks ):

* Crystal mode: DC~20MHz at 5V, DC~8MHz at 3.2V.

* ERC mode: DC~4MHz at 5V, DC~4MHz at 3.2V.

? Low power consumption:

* Less then 1.6 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:

* 18 pin DIP 300mil : EM78P156EHP

* 18 pin SOP 300mil : EM78P156EHM

* 20 pin SSOP 209mil : EM78P156EHAS

* 20 pin SSOP 209mil : EM78P156EHKM

? 99.9 single instruction cycle commands

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