YTD436 is a high-performance communication LSI for the ISDN BRI user-network interface function (digital four-wire time-division full-duplex operation), supporting D channel layer 1 and layer 2 functions in one 100-pin SQFP chip.

Features
1. Layer 1 function
• Conforms to ITU-T Recommendation I.430 (1992 edition) and
   TTC Standard JT-I430 (1997 edition) (default)
      - 192 kbps transmission rate
      - Interface structure : 2B + D (B = 64 kbps, D = 16 kbps)
      - Frame assembling and disassembling function
      - Collision control (built-in random number (Ri) reset),
         priority control (built-in retransmission control), and state transition control
      - Programmable T3 and T4 timers
• Supports ETSI ETS 300 012 (April 1992) and ANSI T1.605 operating modes
• Leased line capability (JT-I430-a)
• Built-in driver and receiver
   - I.430 TTL interface (when the driver / receiver is disconnected)
   - No external relay or common-mode choke needed
   - Supports 1-to-2 pulse transformer
• Abundant Test functions (for testing and maintenance)
   - Demo mode in which no switch simulator is needed.
   - Three kinds of loop-back modes (Loop-back 1 to 3)
   - INFO signals output for testing
   - Test pulse output for pulse shape check
• Multiframing capability
• INFO1 transmission and INFO4 reception monitor pins
• Power down monitor pin
• I.430 transmission frame phase adjustment function