DESCRIPTION
●The SM3518 is a CMOS 4-bit single-chip microcomputer for databank incorporating data memory RAM, LCD driver (the output is adjustable in 16 steps for various contrast), key/switch input circuit, 8-bit parallel I/O port, 2 output ports and buzzer output circuit. The chip also has memory expansion controlling feature. One of two ports contains speial output circuit for infrared (IR) communication. By connecting an external crystal, a 1 Hz timer is made possible for easier clock function.
●FEATURES
●• ROM capacity :
● Program ROM 12 k x 23 bits
● Character ROM 6 x 8 x 256 bits
● Constant ROM 1 k x 4 bits
●• RAM capacity :
● Working RAM 256 x 4 bits
● Display RAM 74 x 16 bits
● Data RAM 3 k x 8 bits
●• Memory expansion (external) : 1M x 8 bits x 3
●• LCD display : 74 - segment x 16 - common
●• I/O ports :
● Parallel I/O 8 bits
● Input 2 bits
● Output 2 bits
● Buzzer output 1 bit (4 kHz)
● Key input 6 bits
●• Standby release : 2 events (2 Hz signal, key input)
●• Built-in oscillator :
● System clock (built-in CR oscillator) 1 MHz
● (external ceramic resonator) 1 MHz
● Timer (built-in CR oscillator) 32.8 kHz
● (external crystal) 32.768 kHz
●• Instruction cycle time : 3 µs
●• Operating temperature : –10 to +60°C
●• Supply voltage : 2.5 to 5.5 V
●• Package : 128-pin QFP (QFP128-P-2828)
● [Test Sample only]
