Chapter 6. MPC8240 Memory Interface
6-47
FPM or EDO DRAM Interface Operation
Some address and control signals may or may not require buffering, depending upon the
system design. Analysis of the MPC8240 AC specifications, desired memory operating
frequency, capacitive loads, and board routing loads assist the system designer in deciding
whether any signals require buffering. See the
MPC8240 Hardware Specifications
for more
information.
Figure 6-30. Example 16-Mbyte DRAM System with Parity—64-Bit Mode
CAS0
CAS1
CAS2
CAS3
RAS
WE
A[0:9]
DQ[0:35]
SIMM
RAS[2:7]
RAS[1]
RAS[0]
CAS[4]
WE
MPC8240
Buffers
4Mx36
SDMA[12:0]
PAR[0:7]
MDH[0:31]
Data path from
Address path to
Data[0:31]
Data[32:63]
Data[32:63]
Data[0:31]
MDL[0:31]
CAS[5]
CAS[6]
CAS[7]
NC
Parity[0:3]
Parity[4:7]
PAR[0:3]
PAR[4:7]
CAS[0]
CAS[1]
CAS[2]
CAS[3]
CAS0
CAS1
CAS2
CAS3
RAS
WE
A[0:9]
DQ[0:35]
SIMM
4Mx36
CAS0
CAS1
CAS2
CAS3
RAS
WE
A[0:9]
DQ[0:35]
SIMM
4Mx36
CAS0
CAS1
CAS2
CAS3
RAS
WE
A[0:9]
DQ[0:35]
SIMM
4Mx36
CAS[4:7]
CAS[0:3]
boot memory
boot memory
RAS[0]
RAS[1]
SDBA[1:0]
Buffers
Address
Signals
(Outputs)
SDMA
9
8
7
6
5
4
3
2
1
0
Logical Names
msb
MA
lsb
9
8
7
6
5
4
3
2
1
0
Содержание MPC8240
Страница 1: ...MPC8240UM D Rev 1 1 2001 MPC8240 Integrated Processor User s Manual ...
Страница 38: ...xviii MPC8240 Integrated Processor User s Manual TABLES Table Number Title Page Number ...
Страница 48: ...xlviii MPC8240 Integrated Processor User s Manual Acronyms and Abbreviations ...
Страница 312: ...6 94 MPC8240 Integrated Processor User s Manual ROM Flash Interface Operation ...
Страница 348: ...7 36 MPC8240 Integrated Processor User s Manual PCI Host and Agent Modes ...
Страница 372: ...8 24 MPC8240 Integrated Processor User s Manual DMA Register Descriptions ...
Страница 394: ...9 22 MPC8240 Integrated Processor User s Manual I2O Interface ...
Страница 412: ...10 18 MPC8240 Integrated Processor User s Manual Programming Guidelines ...
Страница 454: ...12 14 MPC8240 Integrated Processor User s Manual Internal Arbitration ...
Страница 466: ...13 12 MPC8240 Integrated Processor User s Manual Exception Latencies ...
Страница 516: ...16 14 Watchpoint Trigger Applications ...
Страница 538: ...B 16 MPC8240 Integrated Processor User s Manual Setting the Endian Mode of Operation ...
Страница 546: ...C 8 MPC8240 Integrated Processor User s Manual ...
Страница 640: ...INDEX Index 16 MPC8240 Integrated Processor User s Manual ...