MB86293 Datasheet, PDF (64/285 Pages) Fujitsu Component Limited. – Grraphiics Conttrrollllerr Speciiffiicattiions

FUJITSU LIMITED
PRELIMINARY and CONFIDENTIAL
the external synchronous signal based on the internal PLL must not be used with high speed
synchronous transmit signal.
The synchronization of the horizontal direction is controlled by the following state diagram.
otherwise
Disp
The horizontal resolution counter
= HDP
otherwise
Fporch
Bporch
otherw ise
When the horizontal resolution counter
matches the HTP, it is initialized.
detecting the external horizontal
synchronous signal or
the horizontal synchronous pulse
counter = HSW
Sync
otherwise
The horizontal resolution counter is
is halted, starts to count the horizontal
synchronous pulse counter.
The finite state diagram is controlled by the horizontal resolution counter. The period of outputting
the signal is assigned the Disp state. When the value of the horizontal resolution counter matches
that of the HDP register, it ends to output the signal and the current state is transmitted from Disp
state to Fporch state (front porch). In the Fporch state, when the value of the vertical resolution
register matches that of the HSP register, the current state is transmitted to the Sync state. In this
state, it waits for the horizontal synchronous signal from the external. Coral detects the negative
edge of the horizontal synchronous pulse from the external and synchronizes it. In detecting the
horizontal synchronous signal from the external, the current state is transmitted to the Bporch state
(back porch). The horizontal resolution register does not count in the Sync state, instead the
horizontal synchronous counter is incremented from zero. When the value of this counter matches
the setting value of the HSW register, the current state is transmitted to the Bporch state without
detecting the horizontal synchronous signal form the external. When the value of the horizontal
resolution counter matches that of the HTP register in the Bporch state, the horizontal resolution
counter is reset, and also the current state is transmitted to the Disp state and it begins to display the
next cluster.
MB86293 CORAL_LQ
Graphics Controller
64
Specifications Rev. 1.1