"Date: 03-May-00, 08-May-00, 21-Mar-01
 final version compiled 17/04/01
 mods for v2 compiled 5/12/01
 mods for v3 compiled 13/12/01

 Channel Sounder, Receiver PAL 2
 chspg2v3.txt
 using PLPL
"
DEVICE chspg2 (p22v10)
PIN
clk 	= 1 (CLK_INPUT combinatorial)		"IC16-A"
ace  	= 2 (INPUT combinatorial)		"IC16-A"
go  	= 3 (INPUT combinatorial)		"IC16-A"
read  	= 4 (INPUT combinatorial)		"IC16-A"
a18  	= 5 (INPUT combinatorial)		"IC16-A"
tc25  	= 6 (INPUT combinatorial)		"IC16-A"
oebar  	= 7 (INPUT combinatorial)		"IC16-B"
tc9  	= 8 (INPUT combinatorial)		"IC16-C"
tc17  	= 9 (INPUT combinatorial)		"IC16-D"
a2abar 	= 10 (INPUT combinatorial)		"IC16-E"
wrbar  	= 11 (INPUT combinatorial)		"IC16-G"
scan  	= 13 (INPUT combinatorial)		"IC16-G"
cet18  	= 14 (OUTPUT active_high registered)	"IC16-D"
cet10  	= 15 (OUTPUT active_high registered)	"IC16-C"
roe  	= 16 (OUTPUT active_low combinatorial)	"IC16-B"
zoe  	= 17 (OUTPUT active_low combinatorial)	"IC16-B"
busy  	= 18 (OUTPUT active_high registered)	"IC16-A"
sm0  	= 19 (OUTPUT active_high registered)	"IC16-A"
cs  	= 20 (OUTPUT active_low combinatorial)	"IC16-E"
cstx	= 21 (OUTPUT active_low combinatorial)	"IC16-F"
wrtx	= 22 (OUTPUT active_low combinatorial)	"IC16-G"
oe 	= 23 (OUTPUT active_high combinatorial) "added for v3"

"late change to reduce product terms in pal3...
 WRITE input is now SCAN = old-read + old-write
 so we can define
readinternal= read * scan,
writeinternal = /read * scan;

"
;

DEFINE
readinternal= read * scan,
writeinternal = /read * scan;



"Logic Equation Section"

BEGIN

enable(cet18,cet10,roe,zoe,busy,sm0,cs,cstx,wrtx,oe) = #b1111111111;
reset (cet18,cet10,roe,zoe,busy,sm0,cs,cstx,wrtx,oe) = #b0000000000;
preset(cet18,cet10,roe,zoe,busy,sm0,cs,cstx,wrtx,oe) = #b0000000000;

"		sync SR flipflips are of form
		Q	= /enable * Q
			+ enable * set * /reset
			+ enable * /set * /reset * Q
" 

" added ACE to SM0 and BUSY for version 2
but they are redundant - oops"

sm0 	= /ace * sm0
	+ ace *  go * /(cet18 * ace * a18 + readinternal)
	+ ace * /go * /(cet18 * ace * a18 + readinternal) * sm0 ;


busy	= /ace * busy
	+ ace *  go * /(tc25 * ace)
	+ ace * /go * /(tc25 * ace) * busy ;


zoe 	= sm0 * /oebar ;

roe	= /sm0 * /oebar ;

cet18 	=  ace * tc17  * busy
	+ /ace * cet18 * busy ;

cet10 	=  ace * tc9   * busy
	+ /ace * cet10 * busy ;

cs	= busy * /a2abar ;

cstx	= busy ;

wrtx	= writeinternal * /wrbar ;

oe	= /oebar ;

END.