Chapter 22-272.4.3 Engine Controller2.4.3.1 Engine controller components0008-6354F-2-30a) CPU (IC511)The CPU, with a 32-bit internal bus, operates in synchronization with the 132-MHz internal clock that is generated from a 66-MHz external clock.The CPU is used 8-MB SDRAM (IC508), 8-MB FLASH MEMORY (IC503) and 32-KB EEPROM (IC704). The CPU performs parameter control andhas the following functions.Timer functionThis function is used for the cleaning functions.The internal RTC (IC725) and lithium battery (BAT501) allow the timer to operate even when the AC power supply is off for performing the cleaningfunction.EEPROM control functionIn addition to the EEPROM (IC704) with on-board, it controls the six color independent ink tank EEPROM, maintenance cartridge EEPROM, and headEEPROM.Ink tank level detectionThis function detects the remaining ink level for each color based on the signals from the electrodes mounted on the hollow needle.I/O portThis function performs I/O control from the sensors.b) ASIC (IC512)The ASIC, with a 32-bit internal bus, operates in synchronization with the 100-MHz internal clock that is generated from a 50-MHz external clock.It uses two 32MB SDRAMs and two 8MB SDRAMs having the following functions:System controller communication controlThis function controls communication with the system controller.Image data receptionThis function receives the image data from the system controller and stores it in the SDRAM (IC501, IC502).Image data generation/outputThis function generates the image data for printing each color from the image data received from the system controller and mask pattern corresponding tothe print mode in the SDRAM (IC501, IC502) and stores it in SDRAM (IC506, IC507).This function also controls the output of the generated image data to the carriage relay PCB.Heat enable signal controlThis functions uses the pulse width to perform variable control of the time that the heat enable signal is applied to the nozzle heater board for each nozzlearray in the printhead.Linear scale countThis function reads the linear scale when driving the carriage, divides the 150lpi timing signal by eight to generate the 1200lpi timing signal. It also countsthe linear scale timing cycle using the reference clock to measure the carriage driving speed.Dot countThis function counts the discharge dots used as information for the heat enable signal function, maintenance jet control, cleaning function, and remainingink level for each nozzle array.PWM controlThis function performs driving control of the carriage motor, and suction fan and temperature control of the printhead based on the control signals fromthe CPU.Feed motor controlThis function controls the feed motor speed and position based on the control signals from the CPU.I/O portThis function performs I/O control from the sensors and controls the driving units of the motors, clutch, solenoids, and other parts.c) Driver ASIC (IC705, IC706)The image data generated by the ASIC (IC512) undergoes differential processing to reduce noise and then is sent to the carriage relay PCB.d) SDRAM (IC508)IC506IC707IC507IC503IC508IC704 IC511 IC728 IC729 IC727 IC702IC502 IC501 IC512 IC705 IC706 IC703 IC709IC710