Themis TA64, Руководство по оборудованию

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3-8
Themis Computer
TA64 Hardware Manual
3.1.12 Flash Memory
The TA64 contains both a user and a system Flash memory, both of which are pro-
grammable. A 2-MB system Flash, which serves to boot the system, resides on the
LPC bus, and the 16-MB user Flash resides on the X-bus, which is connected
directly to the FPGA.
The BIOS occupies 512 KB of system memory.
3.2 Memory Subsystem
As seen in Figure 3-3 , the TA64 supports a single custom Themis Memory Module,
plugged directly into the Baseboard. The memory data path is 72 bits with 8 bits
assigned to ECC. Memory complies to PC-133 timing.
Figure 3-3. Custom Memory Module Topology (Side View)
Memory capacities are offered in 1 GB , 2 GB , and 4 GB capacities (see Table 2-1 ,
page 2-3). TA64 memory design includes Error Correction Code (ECC). A single bit
error in a 64-bit word is corrected without loss of a cycle.
In designing the memory subsystem, considerable attention was paid to minimizing
overall power consumption. The typical active power consumption of a TA64 with a
1-GB memory module is 23 watts (see
Table 2-8 on page 2-10 for other power
requirements).
Baseboard
Custom Memory Module
Baseboard
Caution: Because of the VME Specification requiring a 0.8-inch interboard sepa-
ration (see Figure 1-2 on page 1-4) between VME slots, only one Memory Module
can be installed onto a TA64 Baseboard ( stacking is not supported ).