ADSP-BF537 Blackfin Processor Hardware Reference
6-51
External Bus Interface Unit
Bank Activation Command
The bank activation command is required for first access to any internal
bank in SDRAM. Any subsequent access to the same internal bank but
different row will be preceded by a precharge and activation command to
that bank.
However, if an access to another bank occurs, the SDC leaves the current
page open and issues a bank activate command before executing the read
or write command to that bank. With this method, called multibank oper-
ation, one page per bank can be open at a time, which results in a
maximum of 4 pages.
Read/Write Command
A read/write 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 deter-
mined 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
SA10
high during a read or write command.
Write Command With Data Mask
During partial writes to SDRAM, the
SDQM[1:0]
pins are used to mask
writes to bytes that are not accessed.
shows the
SDQM[1:0]
encodings based on the internal transfer address bit
IA[0]
and the transfer
size.
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...