'North Buffer
'This is a final version 4 for ARM Cellputer
'Compatibility code: 2.4
'28.11.08
'PIII version
'Timer implemented

$regfile = "89c2051.dat"
$crystal = 24000000
'$large
'chip sygnature
'North: 1..30
'East:101..130

Const Sgn = 16

Dim D32 As Long
Dim B32(11) As Long
'
'1 - 4 : internal vars
'    5 : internal obj
'6 - 9 : external vars / internal results
'   10 : external obj
'   11 : common 32-bit data
'

Dim Addr As Byte
Dim L32 As Byte
Dim N32 As Byte
Dim Iio As Byte
Dim Jio As Byte
Dim I As Byte
Dim Blcfg As Byte
Dim A1 As Byte
Dim A2 As Byte
Dim Cycles_count As Byte

Dim T0int As Bit
Dim Z As Bit

Config Timer0 = Timer , Gate = Internal , Mode = 1

Declare Sub Bwait_ck(z As Bit)
Declare Sub Bwait_cki(z As Bit)
Declare Sub Bwait_cko(z As Bit)

Declare Sub Rec_host(l32 As Byte , N32 As Byte)
Declare Sub Send_host                                         'Addr is a variable

Declare Sub Rec_int(l32 As Byte , N32 As Byte)
Declare Sub Send_int(l32 As Byte , N32 As Byte)

Declare Sub Rec_ext(l32 As Byte , N32 As Byte)
Declare Sub Send_ext(l32 As Byte , N32 As Byte)

Declare Sub Take_int_data
Declare Sub Give_int_data
Declare Sub Take_ext_data
Declare Sub Give_ext_data

Ledg Alias P3.0                                               'green
En Alias P3.7                                                 'enable pin (output)
Dt Alias P1.0                                                 'data pin (input/output)
Ck Alias P1.1                                                 'clock pin (input)
Cko Alias P1.5                                                'clock (input)
Txo Alias P1.4                                                'transmitter (output)
Rxo Alias P1.3                                                'receiver (input)
Rdo Alias P1.2                                                'ready (output)
Cki Alias P3.5                                                'clock (input)
Txi Alias P3.4                                                'transmitter (output)
Rxi Alias P3.3                                                'receiver (input)
Rdi Alias P3.2                                                'ready (output)
P1 = &B11111111                                               'set all
P3 = &B01111111                                               'reset En

'initialization
On Timer0 Timer_interrupt
Enable Interrupts
Enable Timer0
Priority Set Timer0
Reset T0int

'motherboard selftest
Bitwait Cki , Reset
Reset Ledg
Reset Rdi
Delay
Bitwait Cki , Set
Set Ledg

'communication test
B32(11) = Sgn + 100
Call Send_int(7 , 11)

'external motherboard selftest
Bitwait Cko , Reset
Reset Ledg
Reset Rdo
Delay
Bitwait Cko , Set
Set Ledg

Delay
Set En

'notification to host
Do
  Bitwait En , Set
  Call Rec_host(7 , 11)
  Addr = B32(11)
  If Addr = Sgn Then
     Reset En
     Call Send_host
  End If
  Delay
  Set En
Loop Until Addr = 100

'Command 230: reading and writing input data
'sending data simultaneously to ARM

Do
  Bitwait En , Set
  Call Rec_host(7 , 11)
  Addr = B32(11)
  If Addr = 230 Then
    Reset En
    For I = 1 To 23
      Call Rec_host(15 , 11)
      Call Send_int(15 , 11)
    Next I
    Addr = 255
  End If

  If Addr = Sgn Then
    Reset En
    For I = 1 To 19
      Call Rec_host(15 , 11)
      Call Send_int(15 , 11)
    Next I
    Addr = 255
  End If

  Delay
  Set En
Loop Until Addr = 210


'host rechecking
Do
  Bitwait En , Set
  Call Rec_host(7 , 11)
  Addr = B32(11)
  If Addr = Sgn Then
     Reset En
     Call Send_host
  End If
  Delay
  Set En
Loop Until Addr = 100


'running

'initializations - buffer is empty
B32(5) = 0
B32(10) = 0
Set T0int

Do

   Strt:

   'interrupt occured
   If T0int = 1 Then
      Set Dt
      Set En
      Reset Rdi
      Reset Rdo
      Reset T0int
   End If

   'checking internal ARM
   Set Rdi
   Waitms 10
   If Cki = 0 Then
     Reset Rdi
     Cycles_count = 0
     Start Timer0
     Call Bwait_cki(1)
     Call Rec_int(7 , 11)
     A1 = B32(11)
     Select Case A1
       Case 100 : Call Take_int_data
       Case 200 : Call Give_int_data
     End Select
     Counter0 = 0
     If T0int = 1 Then Goto Strt
   End If
   Reset Rdi

   'checking external ARM
   Set Rdo
   Waitms 10
   If Cko = 0 Then
     Reset Rdo
     Cycles_count = 0
     Start Timer0
     Call Bwait_cko(1)
     Call Rec_ext(7 , 11)
     A2 = B32(11)
     Select Case A2
       Case 100 : Call Take_ext_data
       Case 200 : Call Give_ext_data
     End Select
     Counter0 = 0
   End If
   Reset Rdo

Loop

End

'IO routines

Sub Bwait_ck(z As Bit)
  Do : Loop Until Ck = Z Or T0int = 1
End Sub

Sub Bwait_cki(z As Bit)
  Do : Loop Until Cki = Z Or T0int = 1
End Sub

Sub Bwait_cko(z As Bit)
  Do : Loop Until Cko = Z Or T0int = 1
End Sub

Sub Send_host
    Reset Ledg
    For Iio = 0 To 7
        If T0int = 1 Then Exit For
        Dt = Addr.iio
        Call Bwait_ck(0)
        Call Bwait_ck(1)
    Next Iio
    Set Dt
    Set Ledg
End Sub

Sub Rec_host(l32 As Byte , N32 As Byte)
    D32 = 0
    Reset Ledg
    Set Dt
    For Iio = 0 To L32
        Call Bwait_ck(0)
        D32.iio = Dt
        Call Bwait_ck(1)
    Next Iio
    If T0int = 0 Then B32(n32) = D32
    Set Ledg
End Sub

Sub Send_int(l32 As Byte , N32 As Byte)
    If T0int = 1 Then Exit Sub
    D32 = B32(n32)
    Reset Ledg
    Set Rdi
    For Iio = 0 To L32
        Txi = D32.iio
        Call Bwait_cki(0)
        Delay
        Reset Rdi
        Call Bwait_cki(1)
        If T0int = 1 Then Exit For
        Delay
        Set Rdi
    Next Iio
    Call Bwait_cki(0)
    Delay
    Reset Rdi
    Call Bwait_cki(1)
    Set Ledg
End Sub

Sub Rec_int(l32 As Byte , N32 As Byte)
    D32 = 0
    If T0int = 1 Then Exit Sub
    Reset Ledg
    Set Rdi
    For Iio = 0 To L32
        Call Bwait_cki(0)
        D32.iio = Rxi
        Delay
        Reset Rdi
        Call Bwait_cki(1)
        If T0int = 1 Then Exit For
        Delay
        Set Rdi
    Next Iio
    Call Bwait_cki(0)
    Delay
    Reset Rdi
    Call Bwait_cki(1)
    If T0int = 0 Then B32(n32) = D32
    Set Ledg
End Sub

Sub Send_ext(l32 As Byte , N32 As Byte)
    If T0int = 1 Then Exit Sub
    D32 = B32(n32)
    Reset Ledg
    Set Rdo
    For Iio = 0 To L32
        Txo = D32.iio
        Call Bwait_cko(0)
        Delay
        Reset Rdo
        Call Bwait_cko(1)
        If T0int = 1 Then Exit For
        Delay
        Set Rdo
    Next Iio
    Call Bwait_cko(0)
    Delay
    Reset Rdo
    Call Bwait_cko(1)
    Set Ledg
End Sub

Sub Rec_ext(l32 As Byte , N32 As Byte)
    D32 = 0
    If T0int = 1 Then Exit Sub
    Reset Ledg
    Set Rdo
    For Iio = 0 To L32
        Call Bwait_cko(0)
        D32.iio = Rxo
        Delay
        Reset Rdo
        Call Bwait_cko(1)
        If T0int = 1 Then Exit For
        Delay
        Set Rdo
    Next Iio
    Call Bwait_cko(0)
    Delay
    Reset Rdo
    Call Bwait_cko(1)
    If T0int = 0 Then B32(n32) = D32
    Set Ledg
End Sub

Sub Take_int_data
    For Jio = 1 To 5
      Call Rec_int(31 , Jio)
    Next Jio
    If T0int = 1 Then B32(5) = 0
End Sub

Sub Give_int_data
    For Jio = 6 To 10
      Call Send_int(31 , Jio)
    Next Jio
End Sub

Sub Take_ext_data
    For Jio = 6 To 10
      Call Rec_ext(31 , Jio)
    Next Jio
    If T0int = 1 Then B32(10) = 0
End Sub

Sub Give_ext_data
    For Jio = 1 To 5
      Call Send_ext(31 , Jio)
    Next Jio
End Sub

Timer_interrupt:
   'reset counter
   Counter0 = 0
   'every 33ms
   Inc Cycles_count
   'every 8sec
   If Cycles_count = 250 Then
     Set T0int
   Else
     Start Timer0
   End If
Return
                                                                                                                          '