|author||H. Peter Anvin <firstname.lastname@example.org>||2010-09-18 23:15:42 -0700|
|committer||H. Peter Anvin <email@example.com>||2010-09-18 23:15:42 -0700|
display: during the prefetch interval, run at full speed
We have one character worth of prefetch, but that is one character at full speed (80 columns). So advance the counter at full speed during the prefetch interval. The alternative would be to adjust the timing of the prefetch start dynamically (otherwise the text would move between 40 and 80 column mode), but that seems to be more complicated especially when using the FG unit.
1 files changed, 3 insertions, 1 deletions
@@ -128,7 +128,9 @@ module display (
wire do_hide = wasdble ? washide : ishide;
// Should we advance the character pixel?
- wire advance = width | x;
+ // We need to always advance at full speed during prefetch, or
+ // we would have to start the prefetch earlier in 40-character mode.
+ wire advance = width | x | prefetch;
// Address mapping for 40 and 80 characters
assign a80[3:0] = xchr[3:0];