41316401TH Rev.4 15 /Figure 2-3The engine control block (PU) is controlled by the engine controller board (K71 PWB) whichconsists of a CPU (MSM66Q577), general LSI chip, flash ROM, EEPROM, pulse motor drivers anda video memory (see Figure 2-4).(1) CPUThis, a 16-bit CPU with an AD converter containing 126-Kbyte ROM (OKI MSM66Q577),controls the entire system.(2) General LSIThis LSI (MG63P011-001LA), which is contained in the printer engine control block, has 4Mbits of video memory, and functions such as controller-engine video interfacing, LEDinterfacing, motor control, sensor input, video memory control, main scan color misalignmentcorrection, skew correction and high voltage power supply control.2.2 Engine Controller Board (K71 PWB)K Head I/FY Head I/FM Head I/FC Head I/F8 × Pulse MotorsLSI(VIDEO MEMContaining4Mbit DRAM)High Voltage Power SupplySerial Interface (2 channels)Toner and ID sensors ID checksCU I/FFuse CutDriverEEPROMD/A48MHz32bit Video I/FHeater controlCPU BUSControl Panel4Kbit(512KByte)FLASH256Kbit(32KByte)SRAMCPUMSM66Q577A/D CONDuplexCassette 2/328MHzPaper Feed System Sensors(Paper Feed, Paper Registration,Write and Eject Sensors)MT Sensor (Stage position and paper empty)Cassette 1 Sensor(Paper empty and near empty)Any of Shutter, Clutch, Belt Home andTransparency SensorsBelt and Fuser ChecksCassette SizeAnalog output(Color registration sensor adjustment)Analog input(Temperature variation)Analog InputSwitchAnalog input (Transparencies)Analog input (Various densities)Fan controlCover front/upper openStacker fullTest switch(Power supply cooling)Interruption by motorInterruption by UARTMotor DriverMotor Driver
