VHDL Programming

222 Chapter Eight DQ CLK DQ CLK DQ CLK DQ CLK CLK DFFX(0) DFFX(1) DFFX(2) DFFX(N) Z(1) Z(2) Z(N) A B CLK Figure 8-2 Irregular Ge ...

Advanced Topics 223 IF i = 0 GENERATE dffx : dff PORT MAP( a, clk, z(i + 1)); END GENERATE; IF i = (len -1) GENERATE dffx : PORT ...

224 Chapter Eight GENERIC( setup, qrise, qfall, qbrise, qbfall : time); PORT( din, clk : IN std_logic; PORT( q, qb : OUT std_log ...

Advanced Topics 225 ASCII files as files of lines, where a line is a string, terminated by a carriage return. There are procedur ...

226 Chapter Eight This example shows how to read a single integer value from a line, square the value, and write the squared val ...

Advanced Topics 227 The last entry in the input file shows a line with two input values on the line. When the line is read into ...

228 Chapter Eight PORT( next_instr : IN BOOLEAN; PORT( instr : OUT t_instr; PORT( src : OUT INTEGER; PORT( dst : OUT INTEGER); E ...

Advanced Topics 229 If we are not at the end of the file, the process reads in a line from the file into variable aline. Success ...

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Chapter 9 Synthesis One of the best uses of VHDL today is to synthesize ASIC and FPGA devices. This chapter and the next focus o ...

232 Chapter Nine RTL Description Constraints Synthesis Technology Library Gate Level Netlists Figure 9-1 Gate Level Netlist Synt ...

Synthesis 233 Register Register Combinational Logic CLK CLK Clock Datain Dataout Figure 9-2 Register and Cloud Diagram. RTL desc ...

234 Chapter Nine DQ CLK QB EN CLK DIN DOUT Assignment Statement to Dout DQ CLK QB r1 r2 Figure 9-3 Register Transfer Level with ...

Synthesis 235 END inference; In the first version, the registers are instantiated using component instantiation statements that ...

236 Chapter Nine en dout MUX21S q2 FDSR1 q1 FDSR1 dout clk din CP Q D CP A Bz S Q D Figure 9-4 A Gate Level Descrip- tion. libra ...

Synthesis 237 Register Register Combinational Logic CLK CLK Clock Datain Dataout Area = 100 Delay Constraint Clock Constraint Ar ...

238 Chapter Nine There are a number of constraints shown on the diagram including required time constraints, late arrival constr ...

Synthesis 239 Register Register Combinational Logic CLK CLK Clock Datain Dataout drive load Data2 late arrival setup/hold Figure ...

240 Chapter Nine Load Each output can specify a drive capability that determines how many loads can be driven within a particula ...

Synthesis 241 when a particular signal will occur at a node. This is especially important for late arriving signals. Late arrivi ...