HP LaserJet M9040/M9050 Service Manual - Page 152

Formatter system The formatter system provides the following functions: ● Receives and processes data from product interfaces ● Monitors control panel input and relays status information to the control panel and the I/O ● Develops and coordinates data placement and timing with the print engine ● Stores font information and macros ● Communicates with computers The formatter exchanges signals with the DC controller to start the initial rotation period (INTR), to turn on the registration roller drive clutch, and to feed media into the product. When media is positioned for printing, the formatter sends information through the DC controller to the laser/scanner, which turns on and turns off the laser diodes. Formatter hardware The formatter system includes the following components: Table 5-11 Formatter hardware components Component Function ROM Stores fonts and microprocessor control programs RAM Stores printing and font information and temporarily stores print-image data before it sent to the print engine. RAM data is lost when the product is turned off. NOTE: Upgrading RAM improves graphic-intense printing operations, but does not increase the I/O buffer space or the printing speed. NVRAM Stores configuration information. NVRAM is saved with the product is turned off. USB Sends and receives data through USB type B interface connector (connected to the host computer). EIO interface Sends and receives data through EIO slots such as HP Jetdirect, analog fax, and other accessories. Flash memory card The slot is dedicated to firmware. Real time clock This clock is used for the Wake-up time feature. It includes a battery to supply power when the product is turned off. HP Jetdirect Inside (JDI) JDI is an Ethernet interface that is part of the formatter. 134 Chapter 5 Theory of operation ENWW