path: root/static/v10/man5/lde.10.5

.TH LDE 10.5 UCDS
.SH NAME
lde \- logic design expression language format
.SH DESCRIPTION
.I Lde
format contains six declaration areas that must appear
in the following order:
.TP
.B .x
an optional chip declaration area,
.TP
.B .tt
an optional line for use by
.I wcheck and/or
.IR smoke ,
.TP
.B .i
an input declaration area,
.TP
.B .o
an output declaration area,
.TP
.B .f
an optional field declaration area,
.TP
.B .e
and an expression area.
.PP
The
.I lde
language is much like C.
Identifiers may include
.BR +-. .
.I Lde
does not
use ';' to end a statement.
Symbols must be declared before used.
Declaration is by appearance in the
.B .i
or
.B .o
areas or appearance on the left of an
.B =
in the
.B .f
or
.B .e
areas.
Since
.I lde
is an expression language, no flow control (such as
.B if
or
.BR switch )
is allowed.
An expression selector is available;
.I
expra{[[exprb]:]exprc,[[exprd]:]expre,...}
has the value of
.I exprc
if
.I expra
equals
.IR exprb .
If there is no
.I exprb
and there is a colon then
.I exprc
is the default case.
If there is no
.I exprb
and no colon the the pre-incremented value of the prior
value of
.I exprb
is used, the prior value of
.I exprb
is initialized to \-1.
.PP
The chip declaration area may contain two strings,
.IR name and type .
.PP
The
.B .i
and
.B .o
areas contain
.I
identifier
[ '=' or ':' 
.I
numeric_pinnumber
]
(The ':' is used by 
.I
lde \-w
as a mark for externals.)
Some programs use the order of appearance of the
identifiers.
.PP
The field declaration area contains constructions
of the form
.I n_id
=
.I o_id o_id ...
where
.I n_id
is a new identifier for a multibit value the least significant
bit of which is the first old identifier,
.I o_id.
.PP
The expression area contains assignments of expressions to
identifiers.
Identifiers may be modified by a postpended single quote, "'",
in which case a value of one has the meaning "don't_care" for the unmodified
indentifier.
.PP
Numeric values may be passed from the command line, they appear as
.BR $m .
The (zero based)
.RI m th
occurence of
.BI \- n
one the command line substitutes the value
.I n
for the symbol
.BR $m .
.SH EXAMPLES
.IP
.ftCW
.ps8
.vs10
.nf
 /*
  * bkrom
  * classifies the location of the
  * black king.
  * 0-6 manhattan distance to center
  * 7 orig square
  * 8-11 k-side
  * 12-15 q-side
  */
 .x
	bkrom 74S287
 .i
	wkx0 wkx1 wkx2
	wky0 wky1 wky2
	GND1 GND2 GND3
 .o
 	kb0 kb1 kb2 kb3
 .f
	kx = wkx0 wkx1 wkx2
	ky = wky0 wky1 wky2
	kb = kb0 kb1 kb2 kb3
 .e
	xd = (kx) { 3, 2, 1, 0, 0, 1, 2, 3 }
	yd = (ky) { 3, 2, 1, 0, 0, 1, 2, 3 }
	d = xd \+ yd
	kb =
		(ky == 6)?
			(kx) { 12, 13, d, d, d, d, 8, 9 }:
		(ky == 7)?
			(kx) { 14, 15, d, d, 7, d, 10, 11 }:
		d
 /*
  * By convention the output enable term for
  * PAL's is 100 + the corresponding pin number.
  * this example includes a .tt line for use by wcheck.
  */
 .x      Bpal    PAL16L8A
 .tt	iiiiiiiiign222222n2v
 .i
	A0 :	1	A1 :	2	A2 :	3	A3 :	4
	A4 :	5	A5 :	6	A6 :	7	A7 :	8
	A8 :	9
 .o
	SE+ :	12	RNE+ :	13	TD+ :	14	TU+ :	15
	SFSE :	16	Y5 :	17			BRDY :	19
 
	e12 = 112	e13 = 113	e14 = 114	e15 = 115
	e16 = 116	e17 = 117			e19 = 119
 
 .f
	cnt = A0 A1 A2 A3 A4
	ardy = A5
	crdy = A6
	flushb- = A8
	flusha- = A7
 .e
	tmp = ((cnt == 0) ? ardy ? 1 : 0 :
		(cnt == 6) ? (crdy || !flushb-) ? 1 : 0 : 1 )
 
	 /* shift enable + for major data path, also count enable */
	SE+ = !tmp
 
	 /* random number clock enable - */
	RNE+ = !(!flusha- ? 0 : tmp )
 
	 /* transfer down - for ireg */
	TD+ = !((cnt == 0) && ardy)
 
	 /* transfer up + (invert outside) for oreg<0:3> */
	TU+ = !((cnt == 6) && crdy && flushb-)
 
	 /* shift flush status enable */
	SFSE = !(cnt == 3)
 
	 /* ack- back to ardy  */
	Y5 = !!((cnt == 0) && ardy)
 
	 /* ready to A */
	BRDY = !( (cnt == 0)? 1 : 0)

	e12 = 1		e13 = 1		e14 = 1		e15 = 1
	e16 = 1		e17 = 1				e19 = 1
 /*
  * An example using parameter passing and Don't_care
  */
 .x	dram	PAL16R6
 .tt	iiiiiinnngin222222nv
 .i
 	CK:1 OE-:11
 	dreq:2 stall:3 cerr:4 read:5 qword:6
 	rasefb=18 casxfb=17 casyfb=16 wefb=15
 	dsfb0=14 dsfb1=13
 .o
 	rase:18 casx:17 casy:16 we:15
 	ds0:14
 	ds1:13
 .f
 	DS = rase casx casy we ds1 ds0
 	DSfb = rasefb casxfb casyfb wefb dsfb1 dsfb0
 .e
 	X.NCAS = 0100		/* don't care bits	*/
 
 	DC =    0200		/* don't care state	*/
 	S.RAS =  040
 	S.CAS =  020
 	S.NCAS = 010
 	S.WE =	 004
 
 	/* low order 2 bits of state vector	*/
 	A = $0	B = $1	C = $2	D = $3
 	
 	 I0 = C		/* state assignement	*/
 	D10 = S.RAS + A
 	D11 = S.RAS + S.CAS + X.NCAS + B
 	D12 = S.RAS + S.CAS + X.NCAS + A
 	D13 = S.RAS +         S.NCAS + B
 	D23 = S.RAS + B
 	D14 = S.RAS +         S.NCAS + D
 	D24 = S.RAS + D
 	D15 = S.RAS +         S.NCAS + C
 	D25 = B
 	D16 = A
 	D26 = D
 	D31 = S.RAS + S.CAS + X.NCAS        + D
 	D32 = S.RAS + S.CAS + X.NCAS + S.WE + A
 	D33 = S.RAS +         S.NCAS + S.WE + B
 	D43 = S.RAS + S.CAS + X.NCAS + S.WE + B
 	D34 = S.RAS +         S.NCAS + S.WE + D
 	D44 = S.RAS + S.CAS + X.NCAS + S.WE + D
 	D35 = S.RAS +         S.NCAS + S.WE + C
 	D36 = S.WE
 
 	DS- = DSfb {
 		 I0: dreq ? D10 : I0,		/* idle state	*/
 		D10: read ? D11 : D31,
 		D31: stall ? D31 : D32,
 		D32: qword ? (stall ? D32 : D33) : D36,
 		D33: stall ? D43 : D34,
 		D43: stall ? D43 : D34,
 		D34: stall ? D44 : D35,
 		D44: stall ? D44 : D35,
 		D35: D36,
 		D36: I0,
 		D11: stall ? D11 : D12,
 		D12: qword ? D13 : D16,
 		D13: cerr ? D23 : D14,
 		D23: D14,
 		D14: cerr ? D24 : D15,
 		D24: D15,
 		D15: cerr ? D25 : D16,
 		D25: D16,
 		D16: cerr ? D26 : I0,
 		D26: dreq ? D10 : I0,
 		: DC
 		}
 
 	DS = 077 ^ DS-
 	DS' = (DS- == DC ) ? ~0 :
 			((DS- & X.NCAS) ? S.NCAS : 0)
.ft
.ps
.vs
.nf