Bitfields for Intel 82443BX SDRAM Control Register: Bit(s) Description ) 15-10 reserved (0) 9-8 add one-clock delay to idle/pipeline DRAM leadoff when =01 (all other values are illegal) 7-5 SDRAM mode select 000 normal operation 001 issue NOP command on all CPU-to-SDRAM cycles 010 issue All-Banks-Precharge command on all CPU-to-SDRAM cycles 011 issue mode register set command on CPU-to-SDRAM cycles (command is driven on memory address lines, so the proper address must be calculated for each row of memory to drive the correct command; MAx[2:0] must be driven to 010 for burst-of-4 mode, MAx3 to 1 for interleave wrap type, MAx4 to the value of the CAS# latency bit, MAx[6:5] to 01, and MAx[12:7] to 0000000 100 issue CBR cycles on all CPU-to-SDRAM cycles else reserved 4 "SDRAMPWR" specifies how CKE signals are driven for various DRAM configurations; refer to #01145 bit 5 3 Leadoff Command Timing =0 four CS# clocks (100 MHz or 66 MHz desktop if MAA/MAB load > 9) =1 three CS# clocks (66 MHz mobile platforms, or desktop w/ load <= 9) 2 CAS# latency =0 three DCLKs =1 two DCLKs 1 SDRAM RAS# to CAS# delay =0 three clocks =1 two clocks 0 SDRAM RAS# precharge =0 three clocks =1 two clocks SeeAlso: #01142