ADSP-BF535 Blackfin Processor Hardware Reference
18-49
External Bus Interface Unit
TRP = 010
2 clock cycles
TRP = 111
7 clock cycles
Selecting the Write to Precharge Delay (TWR)
The t
WR
value defines the required delay, in number of
SCLK
cycles,
between the time the SDC issues a Write command (drives write data) and
a Precharge command.
This parameter enables the application to accommodate the SDRAM’s
timing requirements.
The
TWR
bits in the SDRAM Memory Global Control register
(
EBIU_SDGCTL
) select the t
WR
value. Any value between 1 and 3
SCLK
cycles
may be selected. For example:
TWR = 00
Reserved
TWR = 01
1 clock cycle
TWR = 10
2 clock cycles
TWR = 11
3 clock cycles
SDRAM Memory Bank Control Register
(EBIU_SDBCTL)
The SDRAM Memory Bank Control register (
Figure 18-15
) includes
external bank-specific programmable parameters. It allows software to
control some parameters of the SDRAM on a per-external-bank basis.
Each external bank can be individually configured for a different size of
SDRAM; however, note that all external banks use the same access timing
parameters, as defined in the SDRAM Memory Global Control register
(
EBIU_SDGCTL
). The
EBIU_SDBCTL
register should be programmed before
power-up and should be changed only when the SDC is idle.
Содержание ADSP-BF535 Blackfin
Страница 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Страница 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 908: ...SDRAM Controller External Bus Interface Unit B 36 ADSP BF535 Blackfin Processor Hardware Reference...