DESCRIPTION

The SM3503 is a CMOS 4-bit single-chip microcomputer for databank incorporating data memory RAM, LCD driver, key input circuit and buzzer output circuit. By connecting an external crystal, a 1Hz timer interrupt is made possible for easier clock function.

FEATURES

• ROM capacity :

   Program ROM 6 k x 23 bits

   Character ROM 5 x 8 x 128 bits

• RAM capacity :

   Working RAM 256 x 4 bits

   Display RAM 60 x 8 bits

   Data RAM 1 k x 8 bits

• LCD display : 60-segment x 8-common

• I/O ports :

   Buzzer output 1 bit (4 kHz)

   Key input 7 bits

• Standby release : 2 events (2 Hz signal, key input)

• Built-in oscillator :

   System clock (built-in CR oscillator) 250 kHz

   Timer (built-in CR oscillator) 32.8 kHz

   (external crystal) 32.768 kHz

• Instruction cycle time : 12 µs

• Operating temperature : –10 to +60°C

• Supply voltage : 2.5 to 3.4 V

• Package : 100-pin QFP (QFP100-P-1420)