inductor_pcell_virtuoso/inductor_2

(defMathConstants 'mconst)
mfgGrid = 100.0
debug = nil

; SNAPS STUFF TO GRID
; uses global mfgGrid to do so, which gets redefined in generator 
; to the tech mfg grid using the techFile
(defun snap (p)
	floor(p*mfgGrid)/mfgGrid
)

; DEBUG output function, uncomment to get all output
(procedure output( @rest args)
	(when debug (apply 'printf args))
	;()
)

; VECTOR HELPER FUNCTIONS
; add a vector vect to a point p
(defun addVect (p vect) 
	(car(p)+car(vect)):(cadr(p)+cadr(vect))
)
; multiplies a vector vect with a scalar
(defun multVect (vect scalar)
	(car(vect)*scalar):(cadr(vect)*scalar)
)
; multiplies a vector vect with -1 (inverse)
(defun invVect (vect)
	(multVect vect -1)
)
; subtracts two vectors from one another
; (does vect2 - vect1)
(defun subVect (vect1 vect2) 
	(car(vect2)-car(vect1)):(cadr(vect2)-cadr(vect1))
)
; returns length of a vector
(defun lenVect (vect)
	sqrt((1.0*car(vect)**2)+(1.0*cadr(vect)**2))
)
; rotates a vector vect by 90 CCW
(defun rotVect (vect)
	cadr(vect):-car(vect)
)
; normalizes a vector vect by its length
(defun normalizeVect (vect)
	(multVect vect 1.0/(lenVect vect))
)

; multiplies a point p with a 2x2 matrix m
(defun matmult (m p)
	result = list()

	for(j 1 2
		temp = 0
		for(i 1 2
			a = nthelem(j nthelem(i m))
			b = nthelem(i p)
			temp += a*b
		)
		result = append(result list(temp))
	)	

	result
)

; DRAWING HELPER FUNCTIONS
; creates a pin using database functions
; and a corresponding net with name name
; does so on the layer layer 
(defun ind_createPin (id name points layer)
	(leCreatePin
		id 
		layer
		"polygon"
		points
		name
		"inputOutput"
		'("none")
	)

	/*
	net = dbCreateNet(id name)
	fig = dbCreatePolygon(id layer points)
	trm = dbCreateTerm(net name "inputOutput")
	pin = dbCreatePin(net fig name trm)
	pin~>accessDir = '( "none" )
	*/

	lab = dbCreateLabel(id '("TEXT") cadr(points) name "centerLeft" "R0" "roman" 3)
	
	;output("created pin %s\n", name)
) 

; Creates the end connection for the inductor and 
; places a pin there
; TODO: create underpass here
(defun ind_createEnd (id start w dir)
	(output "[createEnd] start=%P dir=%P\n", start, dir)
	(let 
		(center points left right up viaDef)
		viaDef = (techFindViaDefByName (techGetTechFile id) "TM2_TM1")
		center = (addVect start (multVect dir (snap -w/2)))
		left = (addVect center (multVect dir (snap -w/2)))
		right = (addVect center (multVect dir (snap w/2)))
		up = (multVect (rotVect dir) (snap w/2))

		points = list(	
			(addVect left up)
			(addVect right up)
			(addVect right (invVect up))
			(addVect left (invVect up))
		)
		
		/*(dbCreateVia
			id 
			viaDef
			(addVect center (multVect dir -w))
			"R0"
			list(
				list("cutWidth" (snap w-0.6))
				list("cutHeight" (snap w-0.6))
			)
		)*/
		
		; create underpass
		/*(dbCreatePathSeg
			id
			underpassLayer
			(addVect center (multVect dir -w))
			(addVect (addVect center (multVect dir -w)) (multVect up -20))
			w*2
			"extend"
			"extend"
		)*/

		/*(ind_createPin 
			id 
			"inner"
			points
			list("TopMetal2" "drawing")
		)*/
	)
)

; Creates the start of the inductor 
; and places a pin there
(defun ind_createStart (id start width dir)
	center = start; (addVect start multVect((invVect dir) width/2))

	points = list(
		(addVect center (-width):width)
		(addVect center width:width)
		(addVect center width:(-width))
		(addVect center (-width):(-width))
	)
	/*(ind_createPin
		id
		"outer"
 		points
		list("TopMetal2" "drawing")
	)*/
)

; creates one segment of the inductor and calls itself recursively to complete
; one inductor
(defun ind_drawSegment (id n seg start r) 
	dx = snap(r*talpha)

	(case mod(seg, 8)
		(0 
			end = dx:r
			)
		(1
			end = r:dx
			)
		(2
			end = r:-dx
			)
		(3
			end = dx:-r		
			)
		(4
			end = -dx:-r
			)
		(5
			end = -r:-dx
			)
		(6
			end = -r:dx
			)
		(7
			r -= pitch
			end = (addVect start (r-dx):(r-dx))
			)
	)
	
	dir = (subVect start end)
	ndir = (normalizeVect dir)

	isstart = (seg == 0)
	isend   = (n < 1)

	; DEBUG
	output("seg: %d, n: %L (start: %L, end: %L)\n", mod(seg, nseg), n, isstart, isend)

	when(isend 
		l = (lenVect dir)
		
		if((mod(seg,2)==0)
		then
			end = addVect(end multVect(ndir (snap l*(n-1))))
		else
			end = addVect(start multVect(ndir (snap l*(n-1))))
		)
	)

	if((mod(seg, 2) == 0)
	then
		(dbCreatePathSeg
			id
			inductorLayer
			start
			end
			w
			if(!isstart then "custom" else "extend")
			if(!isend  then "custom" else "truncate")
			list(if(isstart then 0 else whalv) if(isend then 0 else whalv) list(w2halv w2halv whalv w2halv w2halv whalv))
		)
	else
		(dbCreatePathSeg
			id
			inductorLayer
			start
			end
			w2
			"truncate"
			"truncate"
		)
	)

	when(isstart ind_createStart(id start whalv ndir))
	when((n<=1) ind_createEnd(id end whalv ndir))

	n -= 1
	(output "n=%L\n", n)

	(when (n > 0)
		(ind_drawSegment id n seg+1 end r)
	) ; when
)

defun(ind_gndshield (r width pitch gap window)
	(output "draw gnd shield with r=%L and w=%L\n", r, width)

	r2   = r + width
	m = 1/tan(mconst.PI/nseg)
	segw = 2*r/m
	pitch += width

	(defun iszero (x) 
		abs(x) < 1/mfgGrid
	)

	(defun sign (x)
		(if iszero(x)
		then 0
		else 
			(if (x > 0) 
				then 1
				else -1
			)
		)
	)

	(defun cleanup (vect)
		(sign car(vect)):(sign cadr(vect))
	)

	for(n 0 nseg-1
		angle  = mconst.PI*2/nseg * n
		rotmat = list(
				list(cos(angle) -sin(angle)) 
				list(sin(angle) cos(angle))
			)
		
		w1 = width
		w = w1
		(when ((mod n 2) == 1)
			w2 = w1*sqrt(2)
			w= w2
		)
		
		w1 = (snap w1)
		w2 = (snap w2)
		
		w = (snap w)
		
;		contact_ring = append(contact_ring list(list(r2*cos(angle-mconst.PI/nseg) r2*sin(angle-mconst.PI/nseg))))

		for(y 0 floor(segw/(2*pitch))
			yr = (snap y*pitch)
			a = (snap min(yr*m + gap, r))
			l = (r-a)
			
			(when ((mod n 2) == 1)
				l /= sqrt(2)
			)

			l = (snap l)
			
	
			dir = (cleanup matmult(rotmat 0:-1))
			
			(output "%P\n", dir)

			start = matmult(rotmat yr:r)
			start = (floor((car start)*50.0)/50.0):(floor((cadr start)*50.0)/50.0)
			end = (addVect start (multVect dir l))
	
			(dbCreatePathSeg
				id 
				gndshield_layer
				start 
				end 
				w
				"truncate"
				"truncate"
			)

			when(y != 0
				start = -car(start):cadr(start)
				end = -car(end):cadr(end)

				dbCreatePathSeg(
					id 
					gndshield_layer
					start
					end
					w
					"truncate"
					"truncate"
				)
			)
		) ; for
		
		a = (floor r/m*mfgGrid/2)/(0.5*mfgGrid)
		b = (snap r)

		start = 0:0	
		end = 0:0
		(print n)

		(case n
		(0
			start = -a:b
			end   = a:b
			)
		(1
			start = b:-a
			end   = a:-b
			)
		(2 
			start = b:-a
			end   = b:a
			)
		(3
			start =  a:b
			end   =  b:a
			)
		(4
			start =  a:-b
			end   = -a:-b
			)
		(5
			start = -a:-b
			end   = -b:-a
			)
		(6
			start = -b:-a
			end   = -b:a
			)
		(7
			start = -b:a
			end   = (addVect -a:b -window:-window)
			)
		)

		; draw contact ring
		(apply 'dbCreatePathSeg
				id
				gndshield_layer 
				start
				end
				w
				if(mod(n 2)==0
					then list(
						"truncate"
						"truncate"
						list(0 0)
					)
				else list(
					"custom"
					(if n==7 then "truncate" else "custom")
						list(
							w1/2	
							(if n==7 then 0 else w1/2)
							list(w1/2 w1/2 w2/2 w1/2 w1/2 w2/2)
						)
					)
				)
			)
		)
	)

)

; uses ind_drawSegment to create a complete inductor with 
; the given specification
defun(drawInductor (n r width pitch)
	; the PCell cell view id
	id    = pcCellView

	(when (not id)
		(error "could not find cell view")
	) ; when


	; set multiple globals
	inductorLayer = '("TopMetal2", "drawing")
	underpassLayer = '("TopMetal1", "drawing")
	output("generating inductor with r=%L, turns=%L, pitch=%L and width=%L\n" r n pitch width)

	whalv  = snap(width/2)
	w      = whalv*2
	; diagonal segment width 
	w2halv = snap(width*sqrt(2)/2)   
	w2     = 2*w2halv 


	pitch  = snap(pitch + w) ; pitch from segment sides
	r = snap(r - whalv)   ; middle radius
	nseg   = 8     ; octagonal inductor

	; calculation globals
	ahalv = mconst.PI/nseg            ; angle between segments
	talpha = tan(ahalv)      
	hl    = snap((r-w/2)*talpha) ; start point

	; draw inductor
	(ind_drawSegment id n*nseg 0 -hl:r r)
)

(defun drawGndShield (r pitch width window) 
	; setup gndshield
	id = pcCellView
	gndshield_layer = '("Metal1" "drawing")
	nseg = 8

	(ind_gndshield r pitch width width*2 (snap window))
)

(defun setup ()
	; get manufacturing grid spacing and set global accordingly
	mfgGrid=1/techGetMfgGridResolution(techGetTechFile(pcCellView))
	(output "using manufacturing grid of %L\n", mfgGrid)
)

; defines the inductor PCell 
(pcDefinePCell 
	list( (ddGetObj "mmic14_inductors") "inductorPcell" "layout")
	list(
		( turns  "float" 1.0 )
		( radius "float" 100.0 )
		( width  "float" 2.1 ); techGetSpacingRule(techGetTechFile(pcCellView) "minWidth" "TopMetal2" ))
		( pitch  "float" 2.1 )
		( gndshield "boolean" nil )
		( gndpitch "float" 2.1 )
		( gndwidth "float" 2.1 )
		( gndoverlap "float" 3 )
		( gndwindow "float" 2.1 )
	)
	(let 
		()
		(setup)
		(drawInductor turns radius width pitch)
		(when gndshield 
			(drawGndShield radius+gndoverlap gndwidth gndpitch gndwindow)
		)
	)
)