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atimach64gx: Move pixel clock calculation.

This commit is contained in:
joevt 2024-02-28 01:48:16 -08:00 committed by dingusdev
parent 1fb9e37ec5
commit ab647ec0eb
1 changed files with 11 additions and 6 deletions
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17
devices/video/atimach64gx.cpp
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@ -526,6 +526,16 @@ void AtiMach64Gx::crtc_update()
need_recalc = true;
}
// pixel clock = source_freq / post_div
int m = 8 >> (this->dac_regs[Rgb514::F0_M0] >> 6);
int vco_div = (this->dac_regs[Rgb514::F0_M0] & 0x3F) + 65;
int ref_div = (this->dac_regs[Rgb514::F1_N0] & 0x1F) * m;
float new_pixel_clock = ATI_XTAL * vco_div / ref_div;
if (new_pixel_clock != this->pixel_clock) {
this->pixel_clock = new_pixel_clock;
need_recalc = true;
}
if (!need_recalc)
return;
@ -603,12 +613,7 @@ void AtiMach64Gx::rgb514_write_ind_reg(uint8_t reg_addr, uint8_t value)
if (value & PLL_ENAB) {
if ((this->dac_regs[Rgb514::PLL_CTL_1] & 3) != 1)
ABORT_F("RGB514: unsupported PLL source");
int m = 8 >> (this->dac_regs[Rgb514::F0_M0] >> 6);
int vco_div = (this->dac_regs[Rgb514::F0_M0] & 0x3F) + 65;
int ref_div = (this->dac_regs[Rgb514::F1_N0] & 0x1F) * m;
this->pixel_clock = ATI_XTAL * vco_div / ref_div;
LOG_F(INFO, "RGB514: dot clock set to %f Hz", this->pixel_clock);
this->crtc_update();
}
break;
case Rgb514::PIX_FORMAT: