Devices Included in this Data Sheet:
‧ AT8PS54E/S56E : EPROM devices
‧ AT8PS54/S56 : Mask ROM devices
FEATURES
‧ Only 42 single word instructions
‧ All instructions are single cycle except for program branches which are two-cycle
‧ 13-bit wide instructions
‧ All ROM/EPROM area GOTO instruction
‧ All ROM/EPROM area subroutine CALL instruction
‧ 8-bit wide data path
‧ 5-level deep hardware stack
‧ Operating speed: DC-20 MHz clock input
DC-100 ns instruction cycle
Device Pins # I/O # EPROM/ROM (Byte) RAM (Byte)
AT8PS54/S54E 18 16 512 49
AT8PS56/S56E 18 16 1K 49
‧ Direct, indirect addressing modes for data accessing
‧ 8-bit real time clock/counter (Timer0) with 8-bit programmable prescaler
‧ Internal Power-on Reset (POR)
‧ Built-in Low Voltage Detector (LVD) for Brown-out Reset (BOR)
‧ Power-up Reset Timer (PWRT) and Oscillator Start-up Timer(OST)
‧ On chip Watchdog Timer (WDT) with internal oscillator for reliable operation and soft-ware watch-dog
enable/disable control
‧ Two I/O ports IOA and IOB with independent direction control (maximum 16 I/O pins)
‧ Soft-ware I/O pull-high/pull-down or open-drain control
‧ One internal interrupt source: Timer0 overflow; Two external interrupt source: INT pin, Port B input change
‧ Wake-up from SLEEP by INT pin or Port B input change
‧ Power saving SLEEP mode
‧ Built-in 8MHz, 4MHz, 1MHz, and 455KHz internal RC oscillator
‧ Programmable Code Protection
‧ Selectable oscillator options:
- ERC: External Resistor/Capacitor Oscillator
- HF: High Frequency Crystal/Resonator Oscillator
- XT: Crystal/Resonator Oscillator
- LF: Low Frequency Crystal Oscillator
- IRC: Internal Resistor/Capacitor Oscillator
- ERIC: External Resistor/Internal Capacitor Oscillator
‧ Wide-operating voltage range:
- EPROM : 2.3V to 5.5V
- ROM : 2.3V to 5.5V