SH7205 Datasheet, PDF (1478/1904 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7200 Series

Section 26 2D Graphics Engine (2DG)
(f) Determining the starting address of the partial resize area to be assigned to the DMAC
by the CPU
• Determining the starting address (Sa) of the source set area
SA
ST
SL
Sa
SH
Full resize set area
on source side
Partial resize set area
on source side
Actually updated area
(update area)
SGP
Figure 26.42 Determination of Starting Address (Sa) of Source Set Area
[Definition]
Sa: Starting address for reading the source data for partial resizing
SA: Starting address for reading the source data for full resizing
SGP: Line pitch in the source plane (a 64-byte boundary)
SGP = ROUNDUP (byte count per pixel) × SH/64 bytes) × 64 bytes
Note: ROUNDUP in the formula indicates rounding up, i.e. taking the nearest integer above the
fractional component.
ST: The number of lines from the starting line for the vertical source read-out area for full
resizing to the top-edge pixel in the vertical source read-out area for partial resizing
SL: The number of pixels from the left-edge pixel for the horizontal source read-out area for full
resizing to the left-edge (starting) pixel in the horizontal source read-out area for partial
resizing
Formula for calculating Sa:
Sa = SA + SGP × ST + SL × (byte count per pixel)
Rev. 1.00 Mar. 25, 2008 Page 1446 of 1868
REJ09B0372-0100