EM78P257
OTP ROM
This specification is subject to change without prior notice.
07.27.2004 (V1.4)
2
Specification Revision History
Version
Content
1.0
Initial version
05/06/2002
1.1
To add AKM/BKM Package type, RC Drift Rate, DC and AC Electrical
Characteristic
03/18/2003
1.2
To remove BKM Package type, Change Power on reset content
06/27/2003
1.3
To add AC, DC curve
05/23/2004
1.4
To remove prescalers from TCCA, TCCB and TCCC
07/27/2004
Application Note
AN-001 EM78P257 Firmware programming for Mouse, Comparator, IR and Change Interrupt. Internal C,
External R Oscillation Mode Application Note
AN-002 EM78P257 applied by Comparator, IR ourput and Mouse separately
EM78P257
OTP ROM
This specification is subject to change without prior notice.
07.27.2004 (V1.4)
3
1. GENERAL DESCRIPTION
EM78P257A/B is an 8-bit microprocessors with low-power, high speed CMOS technology. It features a
2K*13 bits Electrical One Time Programmable Read Only Memory (OTP -ROM) and provides a protect bit
to prevent from intruding on code, as well as 12 Option bits to accommodate user's requirements.
EM78P257
OTP ROM
This specification is subject to change without prior notice.
07.27.2004 (V1.4)
4
2. FEATURES
Operating voltage range: 2.3V~5.5V
Operating temperature range: 0
C~70
C
Operating frequency range: (Base on 2 clocks)
* Crystal mode: DC ~ 20MHz/2clks,5V; DC ~ 8MHz/2clks,3V
* RC mode: DC ~ 4MHz/2clks,5V; DC ~ 4MHz/2clks,3V
Low power consumption:
* less then 1.5 mA at 5V/4MHz
* typical of 15
A, at 3V/32KHz
* typical of 1
A, during the sleep mode
Built-in RC oscillator(4MHz,1MHz,455KHz,32.768KHz)
RC oscillator mode with Internal Capacitor
Programmable oscillator set-up time (1ms:18ms)
Independent Programmable prescaler of WDT.
One configuration register to match the user's requirements, and provide user's ID code for customer use
80
8 on chip registers (SRAM, general purpose register)
2K
13 on chip ROM
Bi-directional I/O ports.
8 level stacks for subroutine nesting
8-bit real time clock/counter (TCC) with selective signal sources, trigger edges, and overflow interrupt.
4 sets of comparators.
Easy-implemented IR (Infrared remote control) application circuit.
Easy-implemented MOUSE application circuit.
Power down (SLEEP) mode
Five interrupt sources
* TCC overflow interrupt
* Input-port status changed interrupt(wake up from the sleep mode)
* External interrupt
* IR OUT interrupt
* Comparators status change interrupt
Programmable free running watchdog timer
8 programmable pull-high I/O pins
EM78P257
OTP ROM
This specification is subject to change without prior notice.
07.27.2004 (V1.4)
5
8 programmable open-drain I/O pins
8 programmable pull-down I/O pins.
Two clocks per instruction cycle.
Package types:
* 18 pin DIP 300mil
: EM78P257AP
* 20 pin DIP 300mil
: EM78P257BP
* 18 pin SOP 300mil
: EM78P257AM
* 20 pin SOP 300mil
: EM78P257BM
* 20 pin SSOP 209mil
: EM78P257AKM
Power on voltage detector available for both EM78P257A and EM78P257B.
PDF 
ZIP