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MPC8240 Integrated Processor User’s Manual
SDRAM Interface Operation
6.2.4 SDRAM Power-On Initialization
At system reset, initialization software must set up the programmable parameters in the
memory interface configuration registers. These include the memory boundary registers,
the memory banks enable register, the memory page mode register, and the memory control
configuration registers (MCCRs). See Chapter 4, “Configuration Registers,” for more
detailed descriptions of the configuration registers. The programmable parameters relevant
to the SDRAM interface are:
•
Memory bank starting and ending addresses (memory boundary registers)
•
Memory bank enables
•
PGMAX—maximum activate to precharge interval (also called row active time or
t
RAS
)
•
SREN—self refresh enable
•
RAM_TYPE—SDRAM, FPM or EDO
•
PCKEN—parity check enable
•
Row address configuration for each bank
•
INLINE_PAR_NOT_ECC select between ECC or parity on the memory bus for
in-line buffer mode only.
•
WRITE_PARITY_CHK—enable write path parity error reporting
•
INLRD_PARECC_CHK_EN—enable in-line read path ECC or parity error
reporting
•
REFINT—interval between refreshes
•
RSV_PG—reserves a page register, thus allowing only three simultaneously open
pages
•
RMW_PAR—enables read-modify-write parity operation
•
BSTOPRE—burst to precharge interval (page open interval)
•
REFREC—refresh recovery interval from last refresh clock cycle to activate
command
•
RDLAT—data latency from read command
•
PRETOACT—precharge to activate interval
•
ACTOPRE—activate to precharge interval
•
BUF_TYPE—selects the data path buffer mode (flow-through, registered, in-line)
•
REGDIMM—enables registered DIMM mode
•
SDMODE—mode register data to be transferred to SDRAM array by the MPC8240
—specifies CAS latency, wrap type, and burst length
•
ACTORW—activate to read or write interval
Summary of Contents for MPC8240
Page 1: ...MPC8240UM D Rev 1 1 2001 MPC8240 Integrated Processor User s Manual ...
Page 38: ...xviii MPC8240 Integrated Processor User s Manual TABLES Table Number Title Page Number ...
Page 48: ...xlviii MPC8240 Integrated Processor User s Manual Acronyms and Abbreviations ...
Page 312: ...6 94 MPC8240 Integrated Processor User s Manual ROM Flash Interface Operation ...
Page 348: ...7 36 MPC8240 Integrated Processor User s Manual PCI Host and Agent Modes ...
Page 372: ...8 24 MPC8240 Integrated Processor User s Manual DMA Register Descriptions ...
Page 394: ...9 22 MPC8240 Integrated Processor User s Manual I2O Interface ...
Page 412: ...10 18 MPC8240 Integrated Processor User s Manual Programming Guidelines ...
Page 454: ...12 14 MPC8240 Integrated Processor User s Manual Internal Arbitration ...
Page 466: ...13 12 MPC8240 Integrated Processor User s Manual Exception Latencies ...
Page 516: ...16 14 Watchpoint Trigger Applications ...
Page 538: ...B 16 MPC8240 Integrated Processor User s Manual Setting the Endian Mode of Operation ...
Page 546: ...C 8 MPC8240 Integrated Processor User s Manual ...
Page 640: ...INDEX Index 16 MPC8240 Integrated Processor User s Manual ...