operating voltage range : 2.3v~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 3v, dc~4mhz at 2.3v.
* erc mode: dc~4mhz at 5v, dc~4mhz at 3v, dc~4mhz at 2.3v.

low power consumption:
* less then 2.0 ma at 5v/4mhz
* typically 15 µa at 3v/32khz
* typically 1 µa during sleep mode

1k x 13 bits on chip rom

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 : em78156ep
  * 18 pin sop(soic) 300mil : em78156em
  * 20 pin ssop 209mil : em78156eas
  * 20 pin ssop 209mil : em78156ekm
• 99.9% single instruction cycle commands
• the transient point of system frequency between hxt and lxt is around 400khz