mux4.hcl

#/* $begin sim-mux4-raw-hcl */
## Simple example of an HCL file.
## This file can be converted to C using hcl2c, and then compiled.

## In this example, we will generate the MUX4 circuit shown in
## Section SLASHrefLBRACKsect:arch:hclsetRBRACK.  It consists of a control block that generates
## bit-level signals s1 and s0 from the input signal code,
## and then uses these signals to control a 4-way multiplexor
## with data inputs A, B, C, and D.

## This code is embedded in a C program that reads
## the values of code, A, B, C, and D from the command line
## and then prints the circuit output

## Information that is inserted verbatim into the C file
quote '#include <stdio.h>'
quote '#include <stdlib.h>'
quote 'long long code_val, s0_val, s1_val;'
quote 'char **data_names;'

## Declarations of signals used in the HCL description and
## the corresponding C expressions.
boolsig s0 's0_val'
boolsig s1 's1_val'
wordsig code 'code_val'
wordsig  A 'atoll(data_names[0])'
wordsig  B 'atoll(data_names[1])'
wordsig  C 'atoll(data_names[2])'
wordsig  D 'atoll(data_names[3])'

## HCL descriptions of the logic blocks
quote '/* $begin sim-mux4-s1-c */'
bool s1 = code in { 2, 3 };
quote '/* $end sim-mux4-s1-c */'

bool s0 = code in { 1, 3 };

word Out4 = [
	!s1 && !s0 : A;	# 00
	!s1        : B;	# 01
	!s0        : C;	# 10
	1          : D;	# 11
];

## More information inserted verbatim into the C code to
## compute the values and print the output
quote '/* $begin sim-mux4-main-c */'
quote 'int main(int argc, char *argv[]) {'
quote '  data_names = argv+2;'
quote '  code_val = atoll(argv[1]);'
quote '  s1_val = gen_s1();'
quote '  s0_val = gen_s0();'
quote '  printf("Out = %lld\n", gen_Out4());'
quote '  return 0;'
quote '}'
quote '/* $end sim-mux4-main-c */'
#/* $end sim-mux4-raw-hcl */