NAME espresso - input file format for espresso(1OCTTOOLS) DESCRIPTION Espresso accepts as input a two-level description of a Boolean function. This is described as a character matrix with keywords embedded in the input to specify the size of the matrix and the logical format of the input function. Programs exist to translate a set of equations into this format (e.g., eqntott(1OCTTOOLS), bdsyn(1OCTTOOLS), eqntopla(1OCTTOOLS)). This manual page refers to Version 2.3 of Espresso. Comments are allowed within the input by placing a pound sign (#) as the first character on a line. Comments and unrecognized keywords are passed directly from the input file to standard output. Any white-space (blanks, tabs, etc.), except when used as a delimiter in an embedded com- mand, is ignored. It is generally assumed that the PLA is specified such that each row of the PLA fits on a single line in the input file. KEYWORDS The following keywords are recognized by espresso. The list shows the probable order of the keywords in a PLA descrip- tion. [d] denotes a decimal number and [s] denotes a text string. The minimum required set of keywords is .i and .o for binary-valued functions, or .mv for multiple-valued functions. .i [d] Specifies the number of input variables. .o [d] Specifies the number of output functions. .mv [num_var] [num_binary_var] [d1] . . . [dn] Specifies the number of variables (num_var), the number of binary variables (num_binary_var), and the size of each of the multiple-valued vari- ables (d1 through dn). .ilb [s1] [s2] . . . [sn] Gives the names of the binary valued variables. This must come after .i and .o (or after .mv). There must be as many tokens following the key- word as there are input variables. .ob [s1] [s2] . . . [sn] Gives the names of the output functions. This must come after .i and .o (or after .mv). There must be as many tokens following the keyword as there are output variables. .label var=[d] [s1] [s2] ... Specifies the names of the parts of a multiple- valued variable. This must come after .mv. There must be as many tokens following the key- word as there are parts for this variable. Note that the variables are numbered starting from 0. .type [s] Sets the logical interpretation of the character matrix as described below under "Logical Description of a PLA". This keyword must come before any product terms. [s] is one of f, r, fd, fr, dr, or fdr. .phase [s] [s] is a string of as many 0's or 1's as there are output functions. It specifies which polar- ity of each output function should be used for the minimization (a 1 specifies that the ON-set of the corresponding output function should be used, and a 0 specifies that the OFF-set of the corresponding output function should be minim- ized). .pair [d] Specifies the number of pairs of variables which will be paired together using two-bit decoders. The rest of the line contains pairs of numbers which specify the binary variables of the PLA which will be paired together. The binary vari- ables are numbered starting with 0. The PLA will be reshaped so that any unpaired binary variables occupy the leftmost part of the array, then the paired multiple-valued columns, and finally any multiple-valued variables. If the labels have been specified using .ilb, then the variable names may be used instead of the column number. .symbolic [s0] [s1] . . . [sn] ; [t0] [t1] . . . [tm] ; Specifies that the binary-valued variables named [s0] thru [sn] are to be considered as a single multiple-valued variable. Variable [s0] is con- sidered the most significant bit, [s1] the next most significant, and [sn] is the least signifi- cant bit. This creates a variable with 2**n parts corresponding to the decodes of the binary-valued variables. The keywords [t0] thru [tm] provide the labels for each decode of [s0] thru [sn]. ([t0] corresponds to a value of 00...00, [t1] is the value 00...01, etc.). The binary-variables may be identified by column number, or by variable name when .ilb is used. The binary-variables are removed from the func- tion after the multiple-valued variable is created. .symbolic- output [s0] [s1] . . . [sn] ; [t0] [t1] . . . [tm] ; Specifies that the output functions [s0] ... [sn] are to be considered as a single symbolic output. This creates 2**n more output variables corresponding to the possible values of the out- puts. The outputs may be identified by number (starting from 0), or by variable name when .ob is used. The outputs are removed from the func- tion after the new set of outputs is created. .kiss Sets up for a kiss-style minimization. .p [d] Specifies the number of product terms. The pro- duct terms (one per line) follow immediately after this keyword. Actually, this line is ignored, and the ".e", ".end", or the end of the file indicate the end of the input description. .e (.end) Optionally marks the end of the PLA description. LOGICAL DESCRIPTION OF A PLA When we speak of the ON-set of a Boolean function, we mean those minterms which imply the function value is a 1. Like- wise, the OFF-set are those terms which imply the function is a 0, and the DC-set (don't care set) are those terms for which the function is unspecified. A function is completely described by providing its ON-set, OFF-set and DC-set. Note that all minterms lie in the union of the ON-set, OFF-set and DC-set, and that the ON-set, OFF-set and DC-set share no minterms. The purpose of the espresso minimization program is to find a logically equivalent set of product-terms to represent the ON-set and optionally minterms which lie in the DC-set, without containing any minterms of the OFF-set. A Boolean function can be described in one of the following ways: 1) By providing the ON-set. In this case, espresso com- putes the OFF-set as the complement of the ON-set and the DC-set is empty. This is indicated with the key- word .type f in the input file. 2) By providing the ON-set and DC-set. In this case, espresso computes the OFF-set as the complement of the union of the ON-set and the DC-set. If any minterm belongs to both the ON-set and DC-set, then it is con- sidered a don't care and may be removed from the ON-set during the minimization process. This is indicated with the keyword .type fd in the input file. 3) By providing the ON-set and OFF-set. In this case, espresso computes the DC-set as the complement of the union of the ON-set and the OFF-set. It is an error for any minterm to belong to both the ON-set and OFF- set. This error may not be detected during the minimi- zation, but it can be checked with the subprogram "- Dcheck" which will check the consistency of a function. This is indicated with the keyword .type fr in the input file. 4) By providing the ON-set, OFF-set and DC-set. This is indicated with the keyword .type fdr in the input file. If at all possible, espresso should be given the DC-set (either implicitly or explicitly) in order to improve the results of the minimization. A term is represented by a "cube" which can be considered either a compact representation of an algebraic product term which implies the function value is a 1, or as a representa- tion of a row in a PLA which implements the term. A cube has an input part which corresponds to the input plane of a PLA, and an output part which corresponds to the output plane of a PLA (for the multiple-valued case, see below). SYMBOLS IN THE PLA MATRIX AND THEIR INTERPRETATION Each position in the input plane corresponds to an input variable where a 0 implies the corresponding input literal appears complemented in the product term, a 1 implies the input literal appears uncomplemented in the product term, and - implies the input literal does not appear in the pro- duct term. With type f, for each output, a 1 means this product term belongs to the ON-set, and a 0 or - means this product term has no meaning for the value of this function. This type corresponds to an actual PLA where only the ON-set is actu- ally implemented. With type fd (the default), for each output, a 1 means this product term belongs to the ON-set, a 0 means this product term has no meaning for the value of this function, and a - implies this product term belongs to the DC-set. With type fr, for each output, a 1 means this product term belongs to the ON-set, a 0 means this product term belongs to the OFF-set, and a - means this product term has no mean- ing for the value of this function. With type fdr, for each output, a 1 means this product term belongs to the ON-set, a 0 means this product term belongs to the OFF-set, a - means this product term belongs to the DC-set, and a ~ implies this product term has no meaning for the value of this function. Note that regardless of the type of PLA, a ~ implies the product term has no meaning for the value of this function. 2 is allowed as a synonym for -, 4 is allowed for 1, and 3 is allowed for ~. MULTIPLE-VALUED FUNCTIONS Espresso will also minimize multiple-valued Boolean func- tions. There can be an arbitrary number of multiple-valued variables, and each can be of a different size. If there are also binary-valued variables, they should be given as the first variables on the line (for ease of description). Of course, it is always possible to place them anywhere on the line as a two-valued multiple-valued variable. The function size is described by the embedded option .mv rather than .i and .o. A multiple-output binary function with ni inputs and no out- puts would be specified as .mv ni+1 ni no. .mv cannot be used with either .i or .o - use one or the other to specify the function size. The binary variables are given as described above. Each of the multiple-valued variables are given as a bit-vector of 0 and 1 which have their usual meaning for multiple-valued functions. The last multiple-valued variable (also called the output) is interpreted as described above for the output (to split the function into an ON-set, OFF-set and DC-set). A vertical bar | may be used to separate the multiple-valued fields in the input file. If the size of the multiple-valued field is less than zero, than a symbolic field is interpreted from the input file. The absolute value of the size specifies the maximum number of unique symbolic labels which are expected in this column. The symbolic labels are white-space delimited strings of characters. To perform a kiss-style encoding problem, the keyword .kiss should be included in the file. The third to last variable on the input file must be the symbolic "present state", and the second to last variable must be the "next state". As always, the last variable is the output. The symbolic "next state" will be hacked to be actually part of the output. EXAMPLE #1 A two-bit adder which takes in two 2-bit operands and pro- duces a 3-bit result can be described completely in minterms as: # 2-bit by 2-bit binary adder (with no carry input) .i 4 .o 3 0000 000 0001 001 0010 010 0011 011 0100 001 0101 010 0110 011 0111 100 1000 010 1001 011 1010 100 1011 101 1100 011 1101 100 1110 101 1111 110 It is also possible to specify some extra options, such as: # 2-bit by 2-bit binary adder (with no carry input) .i 4 .o 3 .ilb a1 a0 b1 b0 .ob s2 s1 s0 .pair 2 (a1 b1) (a0 b0) .phase 011 0000 000 0001 001 0010 010 . . . 1111 110 .e The option .pair indicates that the first binary-valued variable should be paired with the third binary-valued vari- able, and that the second variable should be paired with the fourth variable. The function will then be mapped into an equivalent multiple-valued minimization problem. The option .phase indicates that the positive-phase should be used for the second and third outputs, and that the nega- tive phase should be used for the first output. EXAMPLE #2 This example shows a description of a multiple-valued func- tion with 5 binary variables and 3 multiple-valued variables (8 variables total) where the multiple-valued variables have sizes of 4 27 and 10 (note that the last multiple-valued variable is the "output" and also encodes the ON-set, DC-set and OFF-set information). .mv 8 5 4 27 10 .ilb in1 in2 in3 in4 in5 .label var=5 part1 part2 part3 part4 .label var=6 a b c d e f g h i j k l m n o p q r s t u v w x y z a1 .label var=7 out1 out2 out3 out4 out5 out6 out7 out8 out9 out10 0-010|1000|100000000000000000000000000|0010000000 10-10|1000|010000000000000000000000000|1000000000 0-111|1000|001000000000000000000000000|0001000000 0-10-|1000|000100000000000000000000000|0001000000 00000|1000|000010000000000000000000000|1000000000 00010|1000|000001000000000000000000000|0010000000 01001|1000|000000100000000000000000000|0000000010 0101-|1000|000000010000000000000000000|0000000000 0-0-0|1000|000000001000000000000000000|1000000000 10000|1000|000000000100000000000000000|0000000000 11100|1000|000000000010000000000000000|0010000000 10-10|1000|000000000001000000000000000|0000000000 11111|1000|000000000000100000000000000|0010000000 . . . 11111|0001|000000000000000000000000001|0000000000 EXAMPLE #3 This example shows a description of a multiple-valued func- tion setup for kiss-style minimization. There are 5 binary variables, 2 symbolic variables (the present-state and the next-state of the FSM) and the output (8 variables total). .mv 8 5 -10 -10 6 .ilb io1 io0 init swr mack .ob wait minit mrd sack mwr dli .type fr .kiss --1-- - init0 110000 --1-- init0 init0 110000 --0-- init0 init1 110000 --00- init1 init1 110000 --01- init1 init2 110001 --0-- init2 init4 110100 --01- init4 init4 110100 --00- init4 iowait 000000 0000- iowait iowait 000000 1000- iowait init1 110000 01000 iowait read0 101000 11000 iowait write0 100010 01001 iowait rmack 100000 11001 iowait wmack 100000 --01- iowait init2 110001 --0-0 rmack rmack 100000 --0-1 rmack read0 101000 --0-0 wmack wmack 100000 --0-1 wmack write0 100010 --0-- read0 read1 101001 --0-- read1 iowait 000000 --0-- write0 iowait 000000 EXAMPLE 4 This example shows the use of the .symbolic keyword to setup a multiple-valued minimization problem. .i 15 .o 4 .ilb SeqActive<0> CacheOp<6> CacheOp<5> CacheOp<4> CacheOp<3> CacheOp<2> CacheOp<1> CacheOp<0> userKernel<0> Protection<1> Protection<0> cacheState<1> cacheState<0> PageDirty<0> WriteCycleIn<0> .ob CacheBusy<0> dataMayBeValid<0> dataIsValid<0> WriteCycleOut<0> .symbolic CacheOp<6> CacheOp<5> CacheOp<4> CacheOp<3> CacheOp<2> CacheOp<1> CacheOp<0> ; FET NA PHY_FET PR32 PRE_FET PW32 RA32 RD32 RD64 RDCACHE RFO32 RFO64 TS32 WR32 WR64 WRCACHE ; .symbolic Protection<1> Protection<0> ; PROT_KRO_UNA PROT_KRW_UNA PROT_KRW_URO PROT_KRW_URW ; .symbolic cacheState<1> cacheState<0> ; CS_Invalid CS_OwnPrivate CS_OwnShared CS_UnOwned ; .p 22 0000001--010110 0001 0000001-1-00110 0001 00001011-01011- 0100 000010111-0011- 0100 0000--001--01-- 0100 0000-10--0-1--- 0100 0000-10-1--1--- 0100 00000-0--0-1--- 0100 00000-0-1--1--- 0100 0000-10--0--1-- 0100 0000-10-1---1-- 0100 00000-0--0--1-- 0100 00000-0-1---1-- 0100 ---1----------- 1000 --1------------ 1000 -1------------- 1000 1-------------- 1000 -------0------- 1000 ----1---------- 1000 -----0--------- 1000 ------0-------- 1000 --------------1 1110 .e