Hardware and Software Design • Manufacturing Services
page 21
In no case are smaller than 64 bit data words written to or read from the SDRAM.
There are no restrictions for page boundaries of the SDRAM. If the initial starting address is placed within x10
before an SDRAM page boundary, then the hardware will process the first part of the transfer as a sequence of
individual transfers then go to burst mode at the page boundary. If the length causes the address to cross a page
boundary then the pipeline will detect this and stop prior to the page boundary, insert the proper control cycles and
restart the burst on the next page. The hardware can handle the different combinations of starting, finishing, and
crossing addresses automatically and at full rate as defined in the specification. If attempting to operate outside
of the specification, then pay attention to the boundary conditions to increase performance. Pages are 0x00-
0x3ff. The memory is sufficiently large that the individual sections can be located on page boundaries. For
performance and maintenance reasons page alignment is recommended.
Address Generator SDRAM Length Registers
0090
ADD0_3
Length CH 0
0094
ADD0_3
Length CH 1
0098
ADD0_3
Length CH 2
009C
ADD0_3
Length CH 3
0190
ADD4_7
Length CH 4
0194
ADD4_7
Length CH 5
0198
ADD4_7
Length CH 6
019C
ADD4_7
Length CH 7
Read – Write
Bit#
Definition
24-0
Length to access SDRAM for Channel x
31-25
unused / undefined
Eight registers at different offsets with the same bit definitions provided for the 0..7 channels.