SDRAM Interface
9-39
External Memory Interface
9.4.9
SDRAM Write
9.4.9.1
TMS320C6201
/
C6202
/
C6701 SDRAM Write
All SDRAM writes have a burst length of one on the ’C6201/C6202/C6701 . The
bank is activated with the row address during the ACTV command. There is no
latency on writes, so data is output on the same cycle that the column address.
Writes to particular bytes are disabled via the appropriate DQM inputs; this fea-
ture allows for byte and halfword writes. Figure 9–26 shows the timing for a three-
word write on the ’C6201/C6202/C6701. Since the default write burst length is
one-word, a new write command is issued each cycle to perform the three word
burst. Following the final write command, the ’C6201/C6202/C6701 inserts an
idle cycle to meet SDRAM timing requirements. The bank is then deactivated
with a DCAB command, and the memory interface can begin a new page ac-
cess. If no new access is pending, the DCAB command is not performed until
the page information becomes invalid (see section 9.4.2). The values on
EA[15:13] during column accesses and the DCAB command are the values
latched during the ACTV command.
Figure 9–26. TMS320C6201/C6202/C6701 SDRAM Three Word Write
Write
Write
Write
D3
D2
D1
CA3
CA2
CA1
BE3
BE2
BE1
SDWE
SDCAS
SDRAS
SDA10
ED[31:0]
EA[15:2]
BE[3:0]
CEx
Clock†
† Clock=SDCLK for ’C6201/C6701.
Clock=CLKOUT2 for ’C6202.