Ricoh AC205 Service Manual - Page 163

CONTROLLER 6.3.2 ASIC A 32Bit RISC processor executes printer and fax functions. Main Function Block • Fully integrated system for embedded applications • LSU interface module, to interface with the PVC or HPVC • 2-channel, general-purpose DMA controller for high speed I/O • Dual memory bus architecture • Operation frequency: AHB bus: 60MHz. Internal system Bus: 120MHz. • Operation voltage: 3.3V • Power on reset time: Less than 5.6 ms 6.3.3 MEMORY The machine has Flash ROM and DRAM memory units. There are 2 SODIMM sockets to allow for additional DRAM or Flash ROM (Postscript Option) installation. • Capacity :16 MB • Access Time : 100nsec 6.3.4 FLASH MEMORY • Records/downloads system program from the PC Interface • Fax for journal list • Memory for one-touch dial • Speed dial list: • Size : 4M Byte • Access Time :70 nsec 6.3.5 SDRAM SDRAM is used for the following: • Swath buffer in printing • Scan buffer in scanning • ECM buffer in fax receiving • System working memory area: • Size: 32MB • Max Frequency: 133MHz 6.3.6 BATTERY BACKUP Backup power is provided by a 3.6V rechargeable lithium battery. This battery provides power to the SDRAM, to retain faxes in memory when main power is cut. The backup power will last up to 43 hours. The battery requires 48 hours to charge. Detailed Descriptions SM 6-9 B273