PLA(5OCTTOOLS) PLA(5OCTTOOLS) NAME pla - Format for physical description of Programmable Logic Arrays. SYNOPSIS pla DESCRIPTION This format is used by programs which manipulate plas to describe the physical implementation. Lines beginning with a `#' are comments and are ignored. Lines beginning with a `.' contain control information about the pla. Currently, the control information is given in the follow- ing order: .i .o .p and optionally, .na (the name to be used for the pla) What follows then is a description of the AND and OR planes of the pla with one line per product term. Connec- tions in the AND plane are represented with a `1' for con- nection to the non-inverted input line and a `0' for con- nection to the inverted input line. No connection to an input line is indicated with 'x', 'X', or '-' with '-' being preferred. Connections in the OR plane are indi- cated by a '1' with no connection being indicated with 'x', 'X', '0', or '-' with '-' being preferred. Spaces or tabs may be used freely and are ignored. The end of the pla description is indicated with: .e Programs capable of handling split and folded arrays employ the following format: AND PLANE Column (1) Contact to input (2) No contact to input (1) (2) 1 - Normal contacts, no splits or folds ! _ Split below ; , Fold to right : . Split below and fold to right OR PLANE Column (1) Contact to output (2) No contact to output (1) (2) I ~ Normal contacts, no splits or folds i = Split below | ' Fold to right j " Split below and fold to right ADDITIONAL ELEMENTS * Input buffer + Output buffer D Depletion load associated with product term N No depletion load associated with product term Note that the decoding function of the AND plane is sepa- rated from the specification of its connectivity. This makes the AND and OR plane specifications identical. These programs handle the following more general set of .parameters: .il .ir .ol .or .p .ilt .ilb .irt .irb .olb .olt .orb .ort .pl .pr The first group of parameters must precede the second group. If there is only one AND or OR plane it is assumed to be the left one and the companion .parameters may be shortened by dropping their (left,right) designation character. In order to better deal with folded and split PLAs, the following .parameters are proposed: .ig .og .ins .inf .ons .onf In order to build finite state machines, the follow- ing .parameters are proposed: .iltf .ilbf .irtf .irbf .oltf .olbf .ortf .orbf .ilr .irr .olrf .orrf The .XXXf parameters must occur in pairs, with the .oXXf line first. Input and output terms must occur on the same side (top, bottom) of the PLA. Feedback terms must be given in ascending order. The re-order .parameters simplify feedback routing. SEE ALSO espresso(1OCTTOOLS), espresso(5OCTTOOLS), misII(1OCTTOOLS) 8/23/81 PLA(5OCTTOOLS)