YTD439 Datasheet, PDF (1/15 Pages) List of Unclassifed Manufacturers – ISDN BRI controller for Terminal Equipment with built-in DSU

YTD439
ISTU
ISDN BRI controller for Terminal Equipment with built-in DSU
❑ Abstract
YTD439 is a LSI that integrates in a single chip all the communication functions that are
necessary for constructing an ISDN terminal with a built-in DSU. The functions of both the DSU
(U reference point) and terminal (S/T reference point) are packed into the 100-pin SQFP chip
allowing miniaturization of the terminal equipment.
YTD439 has a built-in TD switch function that is necessary for controlling the connection of the
B-channel data. By connecting an external CPU, memory, and CODEC, a terminal with a built-in
DSU can be configured. In addition, YTD439 has a function that reduces the power consumption
by stopping the functions of unused blocks. This is effective for battery-driven terminals.
❍ Features
DSU block
• Conforms to TTC Standards JT-I430 and JT-G961.
• LT (line termination) function and CT (circuit termination) function.
• DSU can be disconnected.
S/T reference point driver/receiver block
• Transition to the sleep state possible by setting an I/O register.
CPU interface block
• 8-bit or 16-bit data bus selectable.
• I/O access through registers.
YTD439 CATALOG
CATALOG No.:4TD439A2
2001.1