![Freescale Semiconductor MPC8250 Скачать руководство пользователя страница 453](http://html1.mh-extra.com/html/freescale-semiconductor/mpc8250/mpc8250_family-reference-manual_2330549453.webp)
Memory Controller
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor
11-35
11.4.1
Supported SDRAM Configurations
The PowerQUICC II memory controller supports any SDRAM configuration under the restrictions that all
SDRAM devices that reside on the same bus (60x or local) should have the same port size and timing
parameters. For more information, refer to Application Note 2165, “MPC8260 SDRAM Support” (order
number AN2165/D).
11.4.2
SDRAM Power-On Initialization
At system reset, initialization software must set up the programmable parameters in the memory controller
banks registers (ORx, BRx, P/LSDMR). After all memory parameters are configured, system software
should execute the following initialization sequence for each SDRAM device.
1. Issue a
PRECHARGE
-
ALL
-
BANKS
command
2. Issue eight
CBR
REFRESH
commands
NOTE
If the SDRAM does not require eight
CBR
REFRESH
COMMANDS
, then the
SDRAM requirement should be followed.
3. Issue a
MODE
-
SET
command to initialize the mode register
The initial commands are executed by setting P/LSDMR[OP] and accessing the SDRAM with a
single-byte transaction. See Figure 11-10 on page 11-20.
Note that software should ensure that no memory operations begin until this process completes.
11.4.3
JEDEC-Standard SDRAM Interface Commands
The PowerQUICC II performs all accesses to SDRAM by using JEDEC-standard SDRAM interface
commands. The SDRAM device samples the command and data inputs on the rising edge of the
PowerQUICC II bus clock. Data at the output of the SDRAM device must be sampled on the rising edge
of the PowerQUICC II bus clock.
As seen in
Table 11-19
, the PowerQUICC II provides the following SDRAM interface commands:
Содержание MPC8250
Страница 90: ...MPC8260 PowerQUICC II Family Reference Manual Rev 2 lxxxviii Freescale Semiconductor...
Страница 94: ...MPC8260 PowerQUICC II Family Reference Manual Rev 2 I 4 Freescale Semiconductor...
Страница 118: ...Overview MPC8260 PowerQUICC II Family Reference Manual Rev 2 1 24 Freescale Semiconductor...
Страница 236: ...Reset MPC8260 PowerQUICC II Family Reference Manual Rev 2 5 14 Freescale Semiconductor...
Страница 274: ...60x Signals MPC8260 PowerQUICC II Family Reference Manual Rev 2 7 18 Freescale Semiconductor...
Страница 540: ...IEEE 1149 1 Test Access Port MPC8260 PowerQUICC II Family Reference Manual Rev 2 13 8 Freescale Semiconductor...
Страница 548: ...MPC8260 PowerQUICC II Family Reference Manual Rev 2 IV 8 Freescale Semiconductor...
Страница 704: ...Serial Communications Controllers SCCs MPC8260 PowerQUICC II Family Reference Manual Rev 2 20 26 Freescale Semiconductor...
Страница 770: ...SCC BISYNC Mode MPC8260 PowerQUICC II Family Reference Manual Rev 2 23 20 Freescale Semiconductor...
Страница 808: ...SCC Ethernet Mode MPC8260 PowerQUICC II Family Reference Manual Rev 2 25 24 Freescale Semiconductor...
Страница 848: ...Serial Management Controllers SMCs MPC8260 PowerQUICC II Family Reference Manual Rev 2 27 36 Freescale Semiconductor...
Страница 972: ...ATM Controller and AAL0 AAL1 and AAL5 MPC8260 PowerQUICC II Family Reference Manual Rev 2 30 52 Freescale Semiconductor...
Страница 1062: ...ATM AAL1 Circuit Emulation Service MPC8260 PowerQUICC II Family Reference Manual Rev 2 31 46 Freescale Semiconductor...
Страница 1072: ...ATM AAL2 MPC8260 PowerQUICC II Family Reference Manual Rev 2 32 10 Freescale Semiconductor...
Страница 1122: ...Inverse Multiplexing for ATM IMA MPC8260 PowerQUICC II Family Reference Manual Rev 2 33 20 Freescale Semiconductor...
Страница 1178: ...Inverse Multiplexing for ATM IMA MPC8260 PowerQUICC II Family Reference Manual Rev 2 33 76 Freescale Semiconductor...
Страница 1224: ...Fast Ethernet Controller MPC8260 PowerQUICC II Family Reference Manual Rev 2 35 28 Freescale Semiconductor...
Страница 1242: ...FCC HDLC Controller MPC8260 PowerQUICC II Family Reference Manual Rev 2 36 18 Freescale Semiconductor...
Страница 1302: ...Register Quick Reference Guide MPC8260 PowerQUICC II Family Reference Manual Rev 2 A 4 Freescale Semiconductor...
Страница 1318: ...Reference Manual Rev 1 Errata MPC8260 PowerQUICC II Family Reference Manual Rev 2 B 16 Freescale Semiconductor...
Страница 1356: ...MPC8260 PowerQUICC II Family Reference Manual Rev 2 Index 28 Freescale Semiconductor U U Index...