PCF1174C is a single chip from PHILIPS company, which has a built-in 4.19MHz oscillator and can achieve 12-hour or 24-hour mode.
The Philips PCF1174C is an integrated circuit designed to drive a 4-digit static liquid crystal display (LCD) in car clock applications. It operates at 4.19 MHz and supports both 12-hour and 24-hour modes, with time calibration and LCD voltage regulation being electrically programmable via an on-chip EEPROM.
The device operates within an ambient temperature range of —40 to +85 °C.
Connecting FLASH to Vpp causes the colon to pulse at 1 Hz.
Connecting S1 and S2 to Vss turns all LCD segments ON, but releasing them does not reset the display.