# 2017 Vincent Åström, William Åkerman

.macro	PUSH	reg
	addi	$sp, $sp, -4
	sw	\reg, 0($sp)
.endm

.macro	POP	reg
	lw	\reg, 0($sp)
	addi	$sp, $sp, 4
.endm

	.data
	.global	main
	.global	user_isr
	.globl  loop
	.text

init:
	PUSH	$t0
	li	$t0, 0x0
	li	$s0, 0x0		# lines = 0
	li	$s4, 0xc0		# pixel data
	sb	$t0, 0xbf886100		# TRISE = 0x0
	sb	$t0, 0xbf886110		# PORTE = 0x0
	sw	$t0, 0xbf800800		# T2CON = 0x0
	sw	$t0, 0xbf800810		# TMR2  = 0x0
	li	$t0, 1820
	sw	$t0, 0xbf800820		# PR2   = 1820
	li	$t0, 0x8000
	sw	$t0, 0xbf800808		# T2CONSET = 0x8000
	li	$t0, 0x100
	sw	$t0, 0xbf881060		# IEC0  = 0x100
	li	$t0, 0x4
	sw	$t0, 0xbf8810b0		# IPC2  = 0x4
	ei	# enable interrupts globally
	POP	$t0
	jr	$ra
	nop

	# ----- ----- ----- ----- -----
main:
	jal	init
	nop

	li	$t1, 0x0

loop:
	addi	$t1, $t1, 1

	blt	$s0, 300, cyan
	nop

	j	stuck
	nop
cyan:
	blt	$t1, 40, red
	nop
	li	$s4, 0xfc
	j	loop
	nop
red:
	li	$s4, 0xc3
	j	stuck
	nop

stuck:
	j	stuck
	nop

#starto:	bne	$s4, 0xff, incr
#	nop
#	li	$t8, 0x0
#	loop2:
#	addi	$t8, $t8, 0x1
#	bne	$t8, 0x10000, loop2
#	nop
#	li	$s4, 0xc0
#	j	starto
#	nop
#incr:
#	li	$t8, 0x0
#loop1:
#	addi	$t8, $t8, 0x1
#	bne	$t8, 0x10000, loop1
#	nop

#	addi	$s4, $s4, 0x1
#	j	starto
#	nop

	# ----- ----- ----- ----- -----
user_isr:
	PUSH	$t0

	blt	$s0, 480, r0
	nop
	blt	$s0, 491, r1
	nop
	blt	$s0, 493, r2
	nop
	blt	$s0, 524, r1
	nop

	li	$t0, 0xc0
	sb	$t0, 0xbf886110		# PORTE = 0xc0
	li	$t0, 0x0
ls40:
	addi	$t0, 0x1
	bne	$t0, 40, ls40
	nop

	li	$t0, 0x80
	sb	$t0, 0xbf886110		# PORTE = 0x80
	li	$t0, 0x0
ls41:
	addi	$t0, 0x1
	bne	$t0, 80, ls41
	nop
	li	$t0, 0xc0
	sb	$t0, 0xbf886110		# PORTE = 0xc0
	li	$t0, 0x0
ls42:
	addi	$t0, 0x1
	bne	$t0, 40, ls42
	nop
	li	$t0, 0xc0
	sb	$t0, 0xbf886110		# PORTE = 0xc0

	li	$s0, 0			# lines = 0
	j	endif
	nop

	# ----- ----- ----- ----- -----
r0:
	li	$t0, 0xc0
	sb	$t0, 0xbf886110		# PORTE = 0xc0
	li	$t0, 0x0
l00:
	addi	$t0, 0x1
	bne	$t0, 40, l00
	nop
	li	$t0, 0x80
	sb	$t0, 0xbf886110		# PORTE = 0x80
	li	$t0, 0x0
l01:
	addi	$t0, 0x1
	bne	$t0, 80, l01
	nop
	li	$t0, 0xc0
	sb	$t0, 0xbf886110		# PORTE = 0xc0
	li	$t0, 0x0
l02:
	addi	$t0, 0x1
	bne	$t0, 40, l02
	nop

	li	$t0, 0xf0		# 5
	sb	$s4, 0xbf886110		# PORTE = 0xc3
	j	endif
	nop
	# ----- ----- ----- ----- -----
r1:
	li	$t0, 0xc0
	sb	$t0, 0xbf886110		# PORTE = 0xc0
	li	$t0, 0x0
l10:
	addi	$t0, 0x1
	bne	$t0, 40, l10
	nop
	li	$t0, 0x80
	sb	$t0, 0xbf886110		# PORTE = 0x80
	li	$t0, 0x0
l11:
	addi	$t0, 0x1
	bne	$t0, 80, l11
	nop
	li	$t0, 0xc0
	sb	$t0, 0xbf886110		# PORTE = 0xc0
	li	$t0, 0x0
l12:
	addi	$t0, 0x1
	bne	$t0, 40, l12
	nop
	li	$t0, 0xc0
	sb	$t0, 0xbf886110		# PORTE = 0xc0
	j	endif
	nop
	# ----- ----- ----- ----- -----
r2:
	li	$t0, 0x40
	sb	$t0, 0xbf886110		# PORTE = 0x0
	li	$t0, 0x0
l20:
	addi	$t0, 0x1
	bne	$t0, 40, l20
	nop
	li	$t0, 0x0
	sb	$t0, 0xbf886110		# PORTE = 0x0
	li	$t0, 0x0
l21:
	addi	$t0, 0x1
	bne	$t0, 80, l21
	nop
	li	$t0, 0x40
	sb	$t0, 0xbf886110		# PORTE 0x40
	li	$t0, 0x0
l22:
	addi	$t0, 0x1
	bne	$t0, 40, l22
	nop
	li	$t0, 0x40
	sb	$t0, 0xbf886110		# PORTE = 0x40
	j	endif
	nop
	# ----- ----- ----- ----- -----
endif:
	addi	$s0, $s0, 1		# lines++
	li	$t0, 0x0
	sw	$t0, 0xbf800810		# clear TMR2
	sw	$t0, 0xbf881030		# clear IFS0
	POP	$t0
	jr	$ra
	nop