ModuleWare Reference Guide - Hornad

Sequential PartsConfigurable Counter (cntr)This table is for synchronous high reset.Table 8-15. Configurable Counter Truth Table — Johnson Counter,Synchronous High Resetload clk_en clk rst up_dn count- 0 - - - count- 1 posedge 1 - rst_val1 1 posedge 0 - din0 1 posedge 0 1 if (count not equal to mcount){count, NOT(count[width-1])} > 1; else mcountTable 8-16. Configurable Counter Truth Table — Johnson Counter,Synchronous High Resetup_dn max1 count = mcount0 count = 0Truth Table for LFSR CounterThis table is for asynchronous high reset. Here nmsb is a bit derived from the port count usingthe LFSR derivation polynomial (XOR coefficients), rval is a value derived from the parameterrst_val using the same algorithm.Table 8-17. Configurable Counter Truth Table — LFSR Counter,Asynchronous High Resetload clk_en clk rst count- - - 1 rval- 0 - 0 count1 1 posedge 0 din0 1 posedge 0 {nmsb, count} >> 1This table is for synchronous high reset and positive polarities.Table 8-18. Configurable Counter Truth Table — LFSR Counter, SynchronousHigh Reset, Positive Polaritiesload clk_en clk rst count- 0 - - count- 1 posedge 1 rval186ModuleWare Reference Manual, Library Version 1.9September 18, 2008