A data transfer control device including: a link controller which analyzes
a packet received through a serial bus and generates a packet to be
transmitted through the serial bus; an interface circuit which performs
interface processing between the data transfer control device and a
display driver connected to the data transfer control device through an
interface bus; and a signal detection circuit which detects a vertical
synchronization signal VCIN used for indicating a non-display period of a
display panel and outputs a detection signal VDET. When the link
controller has received a read request packet which requests reading of
status of the VCIN, the link controller waits for the VDET to be output,
and performs processing of transmitting a response packet through the
serial bus on condition that the VDET has been output.