Renesas SH7781 - Manual (Page 1053)

20. Graphics Data Translation Accelerator (GDTA)
Rev.1.00 Jan. 10, 2008 Page 1023 of 1658
REJ09B0261-0100
No. Operation Description
(3) Calculation of
input position
(first row)
The following formulae are used to compute input position (first row) (DDR2-
SDRAM input address).
First row input address formulae
• Y input comparison address
Calculation formula: Past frame Y point value (base point) + [(mbrow
× 16
+ (Recon_down>>1))
× (width + Y padding)] + [mbcol × 16 +
(Recon_right>>1)]
Past frame Y pointer value (base point): MCPYPR setting address
mbrow: Calculated from MCCF setting
mbcol: Calculated from MCCF setting
Recon_down: Calculated from MCCF setting
Recon_right: Calculated from MCCF setting
width: Calculated from MCWR setting
Y padding: Calculated from MCYPR setting
Depending on the motion vector value, 16-dot data (16 bytes) or 17-dot data
(17 bytes) is processed in succession.
Future frame Y pointer address is calculated using a formula similar to that for
the past frame.
* Calculation result for Recon_down>>1 is shown below:
Recon_
down -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
Recon_
down>>1 -3 -3 -2 -2 -1 -1 0 0 1 1 2 2 3
Calculation result for Recon_right>>1 is the same.