![Motorola MPC8240 Скачать руководство пользователя страница 156](http://html.mh-extra.com/html/motorola/mpc8240/mpc8240_user-manual_243927156.webp)
4-28
MPC8240 Integrated Processor User’s Manual
Memory Interface Configuration Registers
4.6.3 Memory Page Mode Register—0xA3
The 1-byte memory page mode register, shown in Figure 4-16 and Table 4-25, contains the
PGMAX parameter which controls how long the MPC8240 retains the currently accessed
page (row) in memory. See Section 6.3.7, “FPM or EDO DRAM Page Mode Retention,” or
Section 6.2.7, “SDRAM Page Mode,” for more information.
Figure 4-16. Memory Page Mode Register—0xA3
5
Bank 5
0
Bank 5
0 Disabled
1 Enabled
4
Bank 4
0
Bank 4
0 Disabled
1 Enabled
3
Bank 3
0
Bank 3
0 Disabled
1 Enabled
2
Bank 2
0
Bank 2
0 Disabled
1 Enabled
1
Bank 1
0
Bank 1
0 Disabled
1 Enabled
0
Bank 0
0
Bank 0
0 Disabled
1 Enabled
Table 4-25. Bit Settings for Memory Page Mode Register—0xA3
Bits
Name
Reset
Value
Description
7–0
PGMAX
All 0s
For DRAM/EDO configurations, the value of PGMAX multiplied by 64 determines the
maximum RAS assertion interval for retained page mode. When programmed to
0x00, page mode is disabled.
For SDRAM configurations, the value of PGMAX multiplied by 64 determines the
activate to precharge interval (sometimes called row active time or t
RAS
) for retained
page mode. When programmed to 0x00, page mode is disabled.
Table 4-24. Bit Settings for Memory Bank Enable Register—0xA0 (Continued)
Bits
Name
Reset
Value
Description
PGMAX
7
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 ...