sed1374 ETC-unknow, sed1374 Datasheet - Page 106

• Manufacturer Part Number: sed1374
• Description: Sed1374 Embedded Memory Color Lcd Controller
• Manufacturer: ETC-unknow

Page 10
SED1374
X26A-G-002-02
for (int loop = 0; loop < 2; loop++)
{
}
// If we still can't hit the frame rate - throw an error.
if ((VNDP < 0) || (VNDP > 0x3F) || (HNDP < 32) || (HNDP > 280))
{
}
for (VNDP = 2; VNDP < 0x3F; VNDP += 3)
{
}
// Divide ClkI and try again.
// (Reg[02] allows us to dived CLKI by 2)
PCLK /= 2;
sprintf("ERROR: Unable to set the desired frame rate.\n");
exit(1);
This routine first performs a formula rearrangement so that HNDP or VNDP can be solved
for. Start with VNDP set to a small value. Loop increasing VNDP and solving the equation
for HNDP until satisfactory HNDP and VNDP values are found. If no satisfactory values
are found then divide CLKI and repeat the process. If a satisfactory frame rate still can’t be
reached - return an error.
In C the code looks like the following snip:
// Solve for HNDP
if ((HNDP >= 32) && (HNDP <= 280))
{
}
HNDP = (PCLK / (FrameRate * (VDP + VNDP))) - HDP;
// Solve for VNDP.
VNDP = (PCLK / (FrameRate * (HDP + HNDP))) - VDP;
// If we have satisfied VNDP then we're done.
if ((VNDP >= 0) && (VNDP <= 0x3F))
goto DoneCalc;
Epson Research and Development
Programming Notes and Examples
Vancouver Design Center
Issue Date: 99/04/27