Motorola MVME2400 用户手册
Block Diagram
http://www.mcg.mot.com/literature
3-15
3
consisting of 18 devices that total 128Mbytes. With 128Mbit (4bit data)
devices, the block contains 256Mbytes. When populated, these blocks
appear as Block A and Block B to the Hawk.
devices, the block contains 256Mbytes. When populated, these blocks
appear as Block A and Block B to the Hawk.
Refer to the MVME2400-Series VME Processor Module Programmer’s
Reference Guide for additional information and programming details.
Reference Guide for additional information and programming details.
SDRAM Latency
The following table shows the performance summary for SDRAM when
operating at 100MHz using PC100 SDRAM with a CAS_latency of 2. The
figure on the next page defines the times that are specified in the table.
operating at 100MHz using PC100 SDRAM with a CAS_latency of 2. The
figure on the next page defines the times that are specified in the table.
Table 3-9. 60x Bus to SDRAM Access Timing (100MHz/PC100 SDRAMs)
ACCESS TYPE
Access Time
(tB1-tB2-tB3-tB4)
Comments
4-Beat Read after idle,
SDRAM Bank Inactive
10-1-1-1
4-Beat Read after idle,
SDRAM Bank Active - Page Miss
12-1-1-1
4-Beat Read after idle,
SDRAM Bank Active - Page Hit
7-1-1-1
4-Beat Read after 4-Beat Read,
SDRAM Bank Active - Page Miss
5-1-1-1
4-Beat Read after 4-Beat Read,
SDRAM Bank Active - Page Hit
2.5-1-1-1
2.5-1-1-1 is an average of 2-
1-1-1 half of the time and 3-
1-1-1 the other half.
1-1-1 half of the time and 3-
1-1-1 the other half.
4-Beat Write after idle,
SDRAM Bank Active or Inactive
4-1-1-1
4-Beat Write after 4-Beat Write,
SDRAM Bank Active - Page Miss
6-1-1-1