SDRAM Machine
MSC8113 Reference Manual, Rev. 0
Freescale Semiconductor
12-17
12.2.5 Bank Interleaving
Bank interleaving is used to achieve a high data rate during switches from one SDRAM row to
another. The SDRAM machine has two modes of interleaving: bank based interleaving and page
based interleaving. Interleaving mode defines which address bits are used as SDRAM bank
selects. According to these address bits, the SDRAM machine performs the interleaving.
The SDRAM interface supports bank interleaving. If a missed page is in a different SDRAM
bank than the currently open page, the SDRAM machine first issues an
ACTIVATE
command to
the new page and later issues a
DEACTIVATE
command to the old page, thus eliminating the
DEACTIVATE
time overhead. Both pages must reside on different SDRAM devices or on different
internal SDRAM banks. The second option can be disabled by setting ORx[IBID]. Set this bit if
the
BNKSEL
signals are not used in 60x-compatible mode.
The bank interleaving feature allows for acceleration of the switching from one SDRAM bank to
another SDRAM bank. If the SDRAM device supports activating new bank before deactivating
the previous bank, the memory controller will use this feature to active the new bank and
deactivate the old bank at optimal timing for maximal data rate. The address bits that select the
bank are controlled by PSDMR[PBI].
The following two methods are used for internal bank interleaving:
Page-Based Interleaving. For use when a long consecutive access to SDRAM is expected.
The access spans more than one SDRAM row. This type of bank interleaving yields the
best performance and is the preferred interleaving method. This method uses low address
bits as the bank select for the SDRAM, thus allowing interleaving on every page
boundary. During the access, the following row to one that is currently accessed is in
different SDRAM bank. This enables page interleaving and maximal data rate.
Page-Based Interleaving is activated by setting PSDMR[PBI] = 1. See Section 12.2.14.1,
SDRAM Configuration Example (Page-Based Interleaving), on page 12-29.
Bank-Based Interleaving. For use when SDRAM accesses are shorter than one SDRAM
row and not consecutive. The most-significant address bits are the bank select for the
SDRAM, thus allowing interleaving only on bank boundaries. Bank-based interleaving is
activated by clearing PSDMR[PBI]. See Section 12.2.14.2, SDRAM Configuration
Example (Bank-Based Interleaving), on page 12-31.
Summary of Contents for MSC8113
Page 1: ...MSC8113 Reference Manual Tri Core 16 Bit Digital Signal Processor MSC8113RM Rev 0 May 2008 ...
Page 20: ...MSC8113 Reference Manual Rev 0 xx Freescale Semiconductor Contents ...
Page 28: ...MSC8113 Reference Manual Rev 0 xxviii Freescale Semiconductor ...
Page 56: ...MSC8113 Reference Manual Rev 0 1 28 Freescale Semiconductor MSC8113 Overview ...
Page 76: ...MSC8113 Reference Manual Rev 0 2 20 Freescale Semiconductor SC140 Core Overview ...
Page 134: ...MSC8113 Reference Manual Rev 0 4 30 Freescale Semiconductor System Interface Unit SIU ...
Page 168: ...MSC8113 Reference Manual Rev 0 6 18 Freescale Semiconductor Boot Program ...
Page 180: ...MSC8113 Reference Manual Rev 0 7 12 Freescale Semiconductor Clocks ...
Page 260: ...MSC8113 Reference Manual Rev 0 8 80 Freescale Semiconductor Memory Map ...
Page 300: ...MSC8113 Reference Manual Rev 0 9 40 Freescale Semiconductor Extended Core ...
Page 304: ...MSC8113 Reference Manual Rev 0 10 4 Freescale Semiconductor MQBus and M2 Memory ...
Page 308: ...MSC8113 Reference Manual Rev 0 11 4 Freescale Semiconductor SQBus ...
Page 590: ...MSC8113 Reference Manual Rev 0 17 46 Freescale Semiconductor Interrupt Processing ...
Page 614: ...MSC8113 Reference Manual Rev 0 18 24 Freescale Semiconductor Debugging ...
Page 622: ...MSC8113 Reference Manual Rev 0 19 8 Freescale Semiconductor Internal Peripheral Bus IPBus ...
Page 724: ...MSC8113 Reference Manual Rev 0 21 32 Freescale Semiconductor UART ...
Page 920: ...MSC8113 Reference Manual Rev 0 25 150 Freescale Semiconductor Ethernet Controller ...
Page 1171: ...MSC8113 Reference Manual Rev 0 Freescale Semiconductor C 61 EF wait_rts P 01077FFC 9F rts 71 ...
Page 1172: ...MSC8113 Reference Manual Rev 0 C 62 Freescale Semiconductor MSC8113 Boot Code ...
Page 1202: ...MSC8113 Reference Manual Rev 0 Index 30 Freescale Semiconductor Index ...