D8254: Programmable Interval Timer

DCD LogoThe D8254 is a programmable interval timer/counter, binary compatible with industry standard 82C54. The D8254 solves one of the most common problems in any microcomputer system, the generation of accurate time delays under software control. The D8254 can be used as a:

  • Real time clock
  • Even counter
  • Digital one-shot
  • Programmable rate generator
  • Square wave generator
  • Binary rate multiplier
  • Complex waveform generator
  • Complex motor controller


  • Three independent 16-bit counters
  • Six programmable Counter modes:
    • Interrupt on terminal count
    • Hardware retriggerable One-Shot
    • Rate Generator
    • Square wave mode
    • Software triggered strobe
    • Hardware triggered strobe
  • Binary or BCD counting
  • Status Read Back Command
  • Simple interface allows easy connection to microcontrollers
  • Fully synthesizable, static design with no internal tri-states

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Block Diagram

Performance and Size

Device Speed grade LUTs/PFUs Fmax
EC -5 527/249 72 MHz
ECP -5 527/249 70 MHz
XP -5 527/249 62 MHz
ispXPGA -4 712/211 59 MHz
ORCA 4 -3 660/116 48 MHz

Ordering Information

This IP core is supported and sold by DCD, contact DCD at support@dcd.pl or visit their website at www.dcd.pl for more information.