Functional Architecture
S875WP1-E TPS
Revision 4.0
6
3.1.1.1
Reset Configuration Logic
The BIOS determines the processor stepping, cache size, and other processor information
through the CPUID instruction. The requirement is for the processor to run at a fixed speed. The
processor cannot be programmed to operate at a lower or higher speed.
On the S875WP1-E platform, the BIOS is responsible for configuring the processor speed. The
BIOS uses CMOS settings to determine which speed to program into the speed setting device.
The processor information is read at every system power-on.
3.1.2 Memory
Subsystem
The server board S875WP1-E provides four DIMM slots and supports a maximum memory
capacity of 4 GB. The DIMM organization is x72, which includes eight ECC check bits. ECC from
the DIMMs are passed through to the processor’s system bus. Memory scrubbing, single-bit
error correction and multiple-bit error detection is supported. Memory can be implemented with
either single-sided (one row) or double-sided (two row) DIMMs.
Table 2. Supported Memory Configurations
DIMM Capacity
Configuration
DDR SDRAM
Density
DDR SDRAM
Organization
Front-side/Back-side
Number of DDR
SDRAM Devices
64 MB
SS
64 Mbit
8 M x 8/empty
8
64 MB
SS
128 Mbit
8 M x 16/empty
4
128 MB
DS
64 Mbit
8 M x 8/8 M x 8
16
128 MB
SS
128 Mbit
16 M x 8/empty
8
128 MB
SS
256 Mbit
16 M x 16/empty
4
256 MB
DS
128 Mbit
16 M x 8/16 M x 8
16
256 MB
SS
256 Mbit
32 M x 8/empty
8
256 MB
SS
512 Mbit
32 M x 16/empty
4
512 MB
DS
256 Mbit
32 M x 8/32 M x 8
16
512 MB
SS
512 Mbit
64 M x 8/empty
8
1024 MB
DS
512 Mbit
64 M x 8/64 M x 8
16
Note:
In the second column, “DS” refers to double-sided memory modules (containing two rows of DDR
SDRAM) and “SS” refers to single-sided memory modules (containing one row of DDR SDRAM).
DIMM and memory configurations must adhere to the following:
•
2.5 V (only) 184-pin DDR SDRAM DIMMs with gold-plated contacts
•
Unbuffered, single-sided or double-sided DIMMs with the following restriction:
•
Double-sided DIMMS with x16 organization are not supported.
•
Maximum total system memory: 4 GB
•
Minimum total system memory: 128 MB
•
ECC and non-ECC DIMMs supported
•
Serial Presence Detect
•
PC3200 (400 MHZ), PC2700 (333 MHZ), and PC2100 (266 MHZ) SDRAM DIMMs