;
; eeprom via i2c read/write
;
; author: hackbard@hackdaworld.org
;

; specify device
.include "../include/m32def.inc"

; ------------------
; interrupt vectors:
; ------------------

; reset
nop
rjmp RESET
; int0
nop
reti
; int1
nop
reti
; int2
nop
reti
; timer 2 compare
nop
reti
; timer 2 overflow
nop
reti
; timer 1 capture
nop
reti
; timer 1 compare a
nop
reti
; timer 1 compare b
nop
reti
; timer 1 overflow
nop
reti
; timer 0 compare
nop
reti
; timer 0 overflow
nop
reti
; spi/stc transfer complete
nop
reti
; usart rx complete
nop
reti
; usart data register empty
nop
reti
; usart tx complete
nop
reti
; adc complete
nop
reti
; eeprom ready
nop
reti
; analog comparator
nop
reti
; twi 
nop
reti
; spm ready
nop
reti

; -----
; code:
; -----

RESET:
; set stackpointer
ldi r16,high(RAMEND)	; write top of ramend (highbyte)
out SPH,r16		; to stackpointer
ldi r16,low(RAMEND)	; write top of ramend (lowbyte)
out SPL,r16		; to stackpointer

; rs232 init
ldi r16,12 	; "76,8k bps @ 16 mhz" in r16
out UBRR,r16 	; write to uart baudrate register
ldi r16,(1<<RXEN)|(1<<TXEN)	; enable rx/tx
out UCSRB,r16	; write to uart control register

; two wire (aka i2c) setup
ldi r16,20	; set period
out TWBR,r16	; write to twi bit rate register
;in r16,TWSR	; get status register
;ori r16,1	; set last bit -> prescaler = 4
;andi r16,0xfd
sbi TWSR,TWPS0
cbi TWSR,TWPS1
;out TWSR,r16	; write to twi status register

ldi r16,(1<<TWEN|1<<TWINT|)
TWCR


; global interrupt enable
sei




; transmit 0x23 all the fucking time ...
ldi r16, 0x23 ; load 0x23 to register
out UDR, r16 ; write that to uart data register port
LOOP:
sbis USR, UDRE
rjmp LOOP
ldi r16, 0x0a
out UDR, r16
rjmp LOOP_H

LOOP_H:
sbis USR, UDRE
rjmp LOOP_H
ldi r16, 0x68
out UDR, r16
rjmp LOOP_D

LOOP_D:
sbis USR, UDRE
rjmp LOOP_D
ldi r16, 0x64
out UDR, r16
rjmp LOOP_W

LOOP_W:
sbis USR, UDRE
rjmp LOOP_W
ldi r16, 0x77
out UDR, r16
rjmp LOOP