SH7205 Datasheet, PDF (1387/1904 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7200 Series

Section 26 2D Graphics Engine (2DG)
• When both SA and SB areas are used, it is assumed that SB (foreground) > SA (background).
For example, if two-plane blending is performed while SB and SA are assumed to be a
character and background, respectively, blending is performed so that the character will always
be foreground.
• If the pixel format for SB area is set to α (4 bits), the SSWIDH bits in GR_SABSET should be
set as follows.
In 16-bit access: For the SSWIDH bits in GR_SABSET, the minimum number of pixels to be
transferred and the pixel transfer unit should be set to 4 and 4 × n (n: arbitrary
integer), respectively. Setting 2 or 3 pixels to these bits is prohibited.
In 32-bit access: For the SSWIDH bits in GR_SABSET, the minimum number of pixels to be
transferred and the pixel transfer unit should be set to 8 and 8 × n (n: arbitrary
integer), respectively.
• If the pixel format is set to αRGB444 or αRGB555, only 16-bit access is enabled when the
total number of pixels to be transferred (SSWIDH × SSHIGH) is odd; both 32-bit and 16-bit
accesses are enabled when the value of SSWIDH × SSHIGH is even. If duplicate-lines are set
for enlargement resizing, either 32-bit access or 16-bit access should be selected according to
the number of pixels on a line (SSWIDH), not according to the total number of pixels to be
transferred (SSWIDH × SSHIGH).
Rev. 1.00 Mar. 25, 2008 Page 1355 of 1868
REJ09B0372-0100