SDRAM Controller (ADSP-2147x/ADSP-2148x)
3-22 ADSP-214xx SHARC Processor Hardware Reference
Precharge All
The precharge all command is given to precharge all internal banks at the
same time before executing an auto-refresh. All open banks are automati-
cally closed. This is possible since the SDC uses a separate SDA10 pin
which is asserted high during this command. This command proceeds the
auto-refresh command. Also, for single bank operation, this command is
used to close any open bank after a page miss detection.
Read/Write
This command is executed if the next read/write access is in the present
active page. During the read command, the SDRAM latches the column
address. The delay between activate and read commands is determined by
the t
RCD
parameter. Data is available from the SDRAM after the CAS
latency has been met.
In the write command, the SDRAM latches the column address. The
write data is also valid in the same cycle. The delay between activate and
write commands is determined by the t
RCD
parameter.
The SDC does not use the auto-precharge function of SDRAMs, which is
enabled by asserting SDA10 high during a read or write command.
To Next Page
Loading...
Need help?
General
