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.TH "FB_GET_HBLANK_BY_HFREQ" "" "06 October 2005" "" ""

.SH NAME
fb_get_hblank_by_hfreq \- get horizontal blank time given hfreq
.SH SYNOPSIS
"SYNOPSIS"
.sp
\fB
.sp
u32 fb_get_hblank_by_hfreq  (u32 \fIhfreq\fB, u32 \fIxres\fB);
\fR
.SH "ARGUMENTS"
.TP
\fB\fIhfreq\fB\fR
horizontal freq
.TP
\fB\fIxres\fB\fR
horizontal resolution in pixels
.SH "DESCRIPTION"
.PP
.PP
xres * duty_cycle
hblank = ------------------
100 - duty_cycle
.PP
duty cycle = percent of htotal assigned to inactive display
duty cycle = C - (M/Hfreq)
.SH "WHERE"
.PP
C = ((offset - scale factor) * blank_scale)
-------------------------------------- + scale factor
256 
M = blank_scale * gradient