SDRAM Interface
9-41
External Memory Interface
9.4.10 TMS320C6211/C6711 Seamless Data Access
Since the ’C6211/C6711 performs data transfers to SDRAM in bursts of 4
words and can maintain up to 4 open pages in a single CE space, this device
is capable of sustaining seamless data transfer to and from multiple pages of
SDRAM. Figure 9–28 shows an example of the ’C6211/C6711 performing two
consecutive burst reads to different pages in a single CE space. The first page
is opened with an ACTV command and after a delay controlled by T
rcd
, the first
read burst begins to bank 0. Since a 4 word burst is done by default, the
’C6211/C6711 takes advantage of the extra cycles by issuing an ACTV com-
mand to open bank 1 while the first read burst takes place. When the first read
burst is scheduled to end, the read burst to bank 1 is issued such that the 3
cycle CAS latency forces data to continue uninterrupted.
Figure 9–28. Burst Reads to 2 Pages of SDRAM
m+1
B1,m
n+3
n+2
n+1
B0,n
R
Cm
R
Cn
B1
B0
BE4
BE3
BE2
BE1
BE4
BE3
BE2
BE1
R
R
B0
SDWE
SDCAS
SDRAS
ED[31:0]
EA12
EA[11:2]
EA[21:13]
BE[3:0]
CEx
ECLKOUT
Á
Á
Á
Á
Read B1, Cn
ACTV B1
Read B0, Cn
ACTV B0
Tcl = 3
Trcd = 3
B1