'{$STAMP BS2}
'------------------------------------------------------------------------
'K STAMP PROGRAM 8 - SENDS CONTROL & RECEIVES STATE

'------------------------------------------------------------------------
'MICROCODE FIELDS AND THEIR MEANING
'
'uinst	OUT	LATCH	MEM_ALU	CY_UPC	UPC_OFFSET
'	0 =None	0 =None			0=None
'address	1 =ACC	1 =ACC	0 =Hi-Z	1=CYF Out	must add
'16-bit	2 =ONE	2 =A	16=Read	2=CYZ Out	this 8-bit
'	4 =ZERO	4  =B	32=Sel		4=CYF Latch	value to
'	8 =PC	8  =PC	48=Write	   0=UPC	"base" to
'	16=MAR	16 =MAR		0=Nop	   1=IR	get address
'	32=MDR	32 =MDR	    	1=Add			of byte in
'	64=TEMP	64 =TEMP		2=And			PIC EEROM
'	128=IR	     		4=Or
'				8=Not
'

'------------------------------------------------------------------------
'DECLARATIONS TO WRITE MICROCODE FIELDS

none		con 0
acc		con 1
one		con 2
zero		con 4
pc		con 8
mar		con 16
mdr		con 32
temp		con 64
ir		con 128
a		con 2
b		con 4
hiz		con 0
mread		con 16
msel		con 32
mwrite	con 48
nop		con 0
gadd		con 1
gand		con 2
gor		con 4
gnot		con 8
cyf		con 16
cyz		con 32
lcyf		con 64
supc		con 0
sir		con 1



'------------------------------------------------------------------------
'MICROCODE
'	     OUT	LATCH	MEM+ALU	CYF+UPC	NEXT UPC
rset	data zero,	pc,	none+nop,	none+supc,	fetch-rset

start	data pc,	a,	none+nop,	none+supc,	m02-rset
m02	data one,	b+acc, none+gadd,	cyz+supc,	m03-rset
m03	data acc,	pc,	none+nop,	none+supc,	fetch-rset

fetch	data pc,	mar,	none+nop,	none+supc,	m05-rset
m05	data mar,	none,	msel+nop,	none+supc,	m06-rset
m06	data none,	mdr,	mread+nop,	none+supc,	incpc-rset

incpc	data pc,	a,	none+nop,	none+supc,	m08-rset
m08	data one,	b+acc, none+gadd,	cyz+supc,	m09-rset
m09	data acc,	pc,	none+nop,	none+supc,	decod-rset

decod	data mdr,	ir,	none+nop,	none+supc,	m0B-rset
m0B	data pc,	mar,	none+nop,	none+supc,	m0C-rset
m0C	data mar,	none,	msel+nop,	none+supc,	m0D-rset
m0D	data none,	mar,	mread+nop,	none+supc,	m0E-rset
m0E	data mar,	none,	msel+nop,	none+sir,	rset-rset



nopm	data none,	none,	none+nop,	none+supc,	fetch-rset

ldam	data none,	mdr,	mread+nop,	none+supc,	m11-rset
m11	data mdr,	temp,	none+nop,	none+supc,	start-rset


m25	data none,	none,	none+nop,	none+supc,	rset-rset
m26	data none,	none,	none+nop,	none+supc,	rset-rset
m27	data none,	none,	none+nop,	none+supc,	rset-rset
m28	data none,	none,	none+nop,	none+supc,	rset-rset
m29	data none,	none,	none+nop,	none+supc,	rset-rset
m2A	data none,	none,	none+nop,	none+supc,	rset-rset
m2B	data none,	none,	none+nop,	none+supc,	rset-rset
m2C	data none,	none,	none+nop,	none+supc,	rset-rset
m2D	data none,	none,	none+nop,	none+supc,	rset-rset
m2E	data none,	none,	none+nop,	none+supc,	rset-rset
m2F	data none,	none,	none+nop,	none+supc,	rset-rset

halt	data 1


'------------------------------------------------------------------------
'MACHINE CODE DECLARATIONS

noop	con %00000000
lda	con %10000000
sta	con %01000000
adda	con %11000000
adca	con %00100000
anda	con %10100000
ora	con %11100000
nota	con %00010000
brc	con %00110000

'------------------------------------------------------------------------
'MAP TABLE

mapped_ir	var byte
index		var byte
nomatch		con 255


'------------------------------------------------------------------------
'CURRENT MICROINSTRUCTION ADDRESS

upc		var byte


'------------------------------------------------------------------------
'GEMINI INSTRUCTION REGISTER & CARRY FLAG "CONNECTION"

ir_		var byte
cyf_		var bit
timer_var	var word

'------------------------------------------------------------------------
'CURRENT MICROINSTRUCTION

reg_out		var byte
reg_latch	var byte

mem_alu		var byte
mem_ops		var mem_alu.nib1
alu_ops		var mem_alu.nib0

cy_upc		var byte
carry_ops	var cy_upc.nib1
upc_sel		var cy_upc.bit0

next_upc	var byte

'------------------------------------------------------------------------
'LINE FEED FOR SERIAL PORT
lf con 10
'------------------------------------------------------------------------

'------------------------------------------------------------------------
'CONTROL LOOP (MOORE MACHINE)
'
'Enter here when BS2 is reset to simulate resetting Gemini uP

reset:	next_upc=rset
	upc_sel=supc
	goto send_uinst

'------------------------------------------------------------------------
'Wait for D Stamp to send IR and CYF

recv_state:

loop:
serin 0, 32, 250, loop, [wait("k"), ir_, cyf_, timer_var]

debug "IR & CYF = "
debug hex2 ir_, " "
debug hex2 cyf_, cr,lf

'------------------------------------------------------------------------
'Send the current microinstruction to the D Stamp

send_uinst:

'Pin 7 connected to green LED that simulates rising edge of clock

high 7

pause timer_var

'SELECT NEXT MICROINSTRUCTION

upc=next_upc
if upc_sel=supc then read_uinst

'else map IR to MICROCODE address
'
index=nomatch
mapped_ir=halt 'if invalid machine instruction
lookdown ir_,=[nop,lda,sta,adda,adca,anda,ora,nota,brc],index
lookup index,[nopm,ldam,stam,addm,adcm,andm,oram,notam,brc0],mapped_ir
upc=mapped_ir

'adjust brc0 address if necessary
'
if ir_<>brc then read_uinst
if cyf_=0 then read_uinst
upc=brc1


read_uinst:

read upc,	reg_out
read upc+1,	reg_latch
read upc+2,	mem_alu
read upc+3,	cy_upc
read upc+4,	next_upc


serout 0,32+$8000,["d",reg_out,reg_latch,mem_alu,cy_upc,next_upc]

low 7

goto recv_state
end