ucl 2.0

# Copyright (c) 2006 by Wayne C. Gramlich.
# All rights reserved.

library $pic16f767
library clock20mhz
library $uart

# Pin definitions:

package pdip
    pin 1 = mclr
    pin 2 = ra0_unused
    pin 3 = ra1_unused
    pin 4 = ra2_unused
    pin 5 = ra3_unused
    pin 6 = ra4_unused
    pin 7 = ra5_unused
    pin 8 = ground
    pin 9 = osc1
    pin 10 = osc2
    pin 11 = rc0_unused
    pin 12 = rc1_unused
    pin 13 = rc2_unused
    pin 14 = rc3_unused
    pin 15 = rc4_unused
    pin 16 = rc5_unused
    pin 17 = tx
    pin 18 = rx
    pin 19 = ground2
    pin 20 = power_supply
    pin 21 = rb0_unused
    pin 22 = rb1_unused
    pin 23 = rb2_unused
    pin 24 = rb3_unused
    pin 25 = rb4_unused
    pin 26 = rb5_unused
    pin 27 = rb6_unused
    pin 28 = rb7_unused

global module_address byte
global rx9d bit
global id_index byte

origin 0

procedure main
    arguments_none
    returns_nothing

    local command byte
    local transmit bit
    local result byte
    local mode byte

    module_address := 5

    # Warm up the UART:
    $trisc@7 := $true
    $trisc@6 := $true

    $txsta := 0
    $tx9 := $true
    #$tx9 := $false
    $txen := $true
    $brgh := $true

    $rcsta := 0
    $spen := $true
    $rx9 := $true
    #$rx9 := $false
    $cren := $true
    #$adden := $true
    $adden := $false

    # Baud rate = 625000 @ 20MHz.
    $spbrg := 1

    mode := 0
    id_index := 0

    #loop_forever
    #	call $uart_byte_put(command)
    #	loop_exactly 100
    #	    delay 500
    #		do_nothing
    #	command := command + 1

    #loop_forever
    #	command := $uart_byte_get()
    #	call $uart_byte_put(command + 1)
    #	call $uart_byte_get()

    loop_forever
	transmit := $false
	rx9d := $false
	while !$rcif
	    do_nothing
	if $rx9d
	    rx9d := $true
	command := $rcreg

	if rx9d
	    # We have an address bit:
	    if command = module_address
		# We have a match:
		$adden := $false
		result := 0x5a
		transmit := $true
	    else
		# We need to disable non-address reception:
		$adden := $true
	    mode := 0	
	else
	    # We have a command:
	    switch mode
	      case 0
		# Basic instruction decoding:
		switch command >> 6
		  case 3
		    # 11xx xxxx:
		    switch (command >> 3) & 7
		      case 7
			# 1111 1xxx:
			switch command & 7
			  case 4
			    # 1111 1100 (Address_Set)
			  case 5
			    # 1111 1101 (Id_Next)
			    transmit := $true
			    result := 0
			    if id_index < id.size
				result := id[id_index]
				id_index := id_index + 1
			    #result := id_index
			  case 6
			    # 1111 1110 (Id_Start)
			    id_index := 0
			    result := 0
			    transmit := $true
			  case 7
			    # 1111 1111 (Deselect):
			    result := 0
			    transmit := $true
			    $adden := $true

	if transmit
	    call $uart_byte_put(result)

	    # Dispose of echoed command in buffer:
	    call $uart_byte_get()


string id = "\16,0,5,1,3,8\Shaft2-A\7\Gramson"