Kodak 700, 630, 500 service manual Memory Circuits, Flash Eeprom

NovaJet 500/630/700 Series Service Manual

The gate array contains the hardware logic for jet firing, monitoring changes in the Carriage Assembly position, controlling DMA through the parallel port, and generating the PWM (Pulse Width Modulation) waveforms for the servo controller.

The gate array is a Xilinx device. It is a static RAM-based field pro- grammable gate array. This means that the logic that it implements is determined by configuration information in an internal RAM storage area. Each time power is turned on, this information must be down- loaded from the system EEROM. This type of gate array allows for the flexibility of upgrading the logic by simply downloading the new system software.

Memory Circuits

Memory is used to retain large amounts of information. This informa- tion is stored in the device memory in the form of binary bits.

Printer memory consists of Flash EEPROM, DRAM, and EEPROM.

Maximum installable memory is as follows:

DRAM = 128 MB

Flash EEPROM = 1 MB

Serial EEPROM = 1KB

Flash EEPROM

Flash EEPROM is Electrically Erasable, Programmable, Read Only Memory used to store instructions and data constants which the microprocessor can access and interpret, with no loss of information when power is off.

2-8 Theory of Operation