'------------------------------------------------------------------------------------
' WebTiger / Ethernut 1.3F - Atmega128 and RTL8019AS - ARP - UDP - PING - HTML
'------------------------------------------------------------------------------------
'
' january 2006 - Ben Zijlstra - Netherlands - https://benshobbycorner.nl/bzijlstra



' Lockbits:
' Lockbit 54 : 11
' Lockbit 32 : 11
' Lockbit 10 : 11

' Fusebits:
' Fusebit 7 : 0
' Fusebit 6 : 0
' Fusebit 98 : 11
' Fusebit DCBA : 1111

' Fusebits High
' Fusebits E : 1
' Fusebits F : 0
' Fusebits G : 0
' Fusebits H : 0
' Fusebits I : 0
' Fusebits KL : 01
' Fusebits M : 1

' Fusebits Extended
' Fusebits P : 1
' Fusebits Q : 1

$regfile "m128def.dat"
$crystal = 14745600
$baud = 57600

$waitstate                                                  'XRAM wait state
$xa                                                         'External Access enabled
$default Xram

'memory map:
'The ATMEGA128 works in normal-mode (fuse-settings)

'Data Memory
'$0000-$001F 32 registers
'$0020-$005F 64 I/O reg.
'$0060-$00FF 160 Ext I/O reg.
'$0100-$10FF Internal SRAM
'$1100-$7FFF External SRAM
'$8300-$831F RTL8019as

$hwstack = 128
$swstack = 128
$framesize = 128

Dim Regaddr As Byte
Dim Regdata As Byte
Dim Byte_read As Byte
Dim Whulp0 As Word
Dim Bhulp0 As Byte
Dim Hulp1 As Byte
Dim Mymac(6) As Byte
Dim Data_l As Byte
Dim Data_h As Byte

Dim Hulp2 As Word
Dim Rxlen As Word
Dim I As Integer
Dim T As Byte
Dim Pageheader(4) As Byte
Dim T_enetpacketlenl As Byte At Pageheader + 2 Overlay
Dim T_enetpacketlenh As Byte At Pageheader + 3 Overlay

Dim Result16 As Word
Dim Result16h As Byte At Result16 + 1 Overlay
Dim Result16l As Byte At Result16 Overlay

Dim Packet(1500) As Byte
'Ethernet packet destination
Dim T_enetpacketdest0 As Byte At Packet Overlay
Dim T_enetpacketdest1 As Byte At Packet + &H01 Overlay
Dim T_enetpacketdest2 As Byte At Packet + &H02 Overlay
Dim T_enetpacketdest3 As Byte At Packet + &H03 Overlay
Dim T_enetpacketdest4 As Byte At Packet + &H04 Overlay
Dim T_enetpacketdest5 As Byte At Packet + &H05 Overlay
'Ethernet packet source
Dim T_enetpacketsrc0 As Byte At Packet + &H06 Overlay
Dim T_enetpacketsrc1 As Byte At Packet + &H07 Overlay
Dim T_enetpacketsrc2 As Byte At Packet + &H08 Overlay
Dim T_enetpacketsrc3 As Byte At Packet + &H09 Overlay
Dim T_enetpacketsrc4 As Byte At Packet + &H0A Overlay
Dim T_enetpacketsrc5 As Byte At Packet + &H0B Overlay
'Ethernet packet type
Dim T_enetpackettype As Word At Packet + &H0C Overlay
Dim T_arp_hwtype1 As Byte At Packet + &H0F Overlay
'Arp
Dim T_arp_prttype1 As Byte At Packet + &H11 Overlay
Dim T_arp_hwlen As Byte At Packet + &H12 Overlay
Dim T_arp_prlen As Byte At Packet + &H13 Overlay
Dim T_arp_op1 As Byte At Packet + &H15 Overlay
'arp source ip address
Dim T_arp_sipaddr0 As Byte At Packet + &H1C Overlay
Dim T_arp_sipaddr1 As Byte At Packet + &H1D Overlay
Dim T_arp_sipaddr2 As Byte At Packet + &H1E Overlay
Dim T_arp_sipaddr3 As Byte At Packet + &H1F Overlay
'arp target IP address
Dim T_arp_tipaddr As Long At Packet + &H26 Overlay
'IP header layout IP version and header length
Dim T_ip_vers_len As Byte At Packet + &H0E Overlay

Dim T_arp_hwtype0 As Byte At Packet + &H0E Overlay
'Arp
Dim T_arp_prttype0 As Byte At Packet + &H10 Overlay
Dim T_arp_op0 As Byte At Packet + &H14 Overlay
'arp source mac address
Dim T_arp_src_enetpacket0 As Byte At Packet + &H16 Overlay
Dim T_arp_src_enetpacket1 As Byte At Packet + &H17 Overlay
Dim T_arp_src_enetpacket2 As Byte At Packet + &H18 Overlay
Dim T_arp_src_enetpacket3 As Byte At Packet + &H19 Overlay
Dim T_arp_src_enetpacket4 As Byte At Packet + &H1A Overlay
Dim T_arp_src_enetpacket5 As Byte At Packet + &H1B Overlay
'arp source mac address
Dim T_arp_dest_enetpacket0 As Byte At Packet + &H20 Overlay
Dim T_arp_dest_enetpacket1 As Byte At Packet + &H21 Overlay
Dim T_arp_dest_enetpacket2 As Byte At Packet + &H22 Overlay
Dim T_arp_dest_enetpacket3 As Byte At Packet + &H23 Overlay
Dim T_arp_dest_enetpacket4 As Byte At Packet + &H24 Overlay
Dim T_arp_dest_enetpacket5 As Byte At Packet + &H25 Overlay
Dim T_tos As Byte At Packet + &H0F Overlay
'packet length
Dim T_ip_pktlen0 As Byte At Packet + &H10 Overlay
Dim T_ip_pktlen1 As Byte At Packet + &H11 Overlay

Dim T_id0 As Byte At Packet + &H12 Overlay
Dim T_id1 As Byte At Packet + &H13 Overlay
Dim T_flags As Byte At Packet + &H14 Overlay
Dim T_offset As Byte At Packet + &H15 Overlay
Dim T_ttl As Byte At Packet + &H16 Overlay

'protocol (ICMP=1, TCP=6, UDP=11)
Dim T_ip_proto As Byte At Packet + &H17 Overlay

'header checksum
Dim T_ip_hdr_cksum0 As Byte At Packet + &H18 Overlay
Dim T_ip_hdr_cksum1 As Byte At Packet + &H19 Overlay
Dim T_ip_hdr_cksum As Word At Packet + &H18 Overlay
'IP address of source
Dim T_ip_srcaddr0 As Byte At Packet + &H1A Overlay
Dim T_ip_srcaddr1 As Byte At Packet + &H1B Overlay
Dim T_ip_srcaddr2 As Byte At Packet + &H1C Overlay
Dim T_ip_srcaddr3 As Byte At Packet + &H1D Overlay

Dim T_ip_srcaddr As Long At Packet + &H1A Overlay

'IP address of destination
Dim T_ip_destaddr0 As Byte At Packet + &H1E Overlay
Dim T_ip_destaddr1 As Byte At Packet + &H1F Overlay
Dim T_ip_destaddr2 As Byte At Packet + &H20 Overlay
Dim T_ip_destaddr3 As Byte At Packet + &H21 Overlay

Dim T_ip_destaddr As Long At Packet + &H1E Overlay

Dim T_icmp_type As Byte At Packet + &H22 Overlay
Dim T_icmp_code As Byte At Packet + &H23 Overlay
Dim T_icmp_cksum0 As Byte At Packet + &H24 Overlay
Dim T_icmp_cksum1 As Byte At Packet + &H25 Overlay
Dim T_icmp_cksum As Word At Packet + &H24 Overlay

Dim Tcp_srcporth As Byte At Packet + &H22 Overlay
Dim Tcp_srcportl As Byte At Packet + &H23 Overlay

Dim Tcp_destporth As Byte At Packet + &H24 Overlay
Dim Tcp_destportl As Byte At Packet + &H25 Overlay

Dim Tcp_seqnum3 As Byte At Packet + &H26 Overlay
Dim Tcp_seqnum2 As Byte At Packet + &H27 Overlay
Dim Tcp_seqnum1 As Byte At Packet + &H28 Overlay
Dim Tcp_seqnum0 As Byte At Packet + &H29 Overlay

Dim Tcp_acknum3 As Byte At Packet + &H2A Overlay
Dim Tcp_acknum2 As Byte At Packet + &H2B Overlay
Dim Tcp_acknum1 As Byte At Packet + &H2C Overlay
Dim Tcp_acknum0 As Byte At Packet + &H2D Overlay

Dim Tcp_hdr As Byte At Packet + &H2E Overlay
Dim Tcp_flags As Byte At Packet + &H2F Overlay
Dim Tcp_cksumh As Byte At Packet + &H32 Overlay
Dim Tcp_cksuml As Byte At Packet + &H33 Overlay
Dim Tcp_cksum As Word At Packet + &H32 Overlay
'UDP header
Dim T_udp_srcport0 As Byte At Packet + &H22 Overlay
Dim T_udp_srcport1 As Byte At Packet + &H23 Overlay

Dim T_udp_srcport As Word At Packet + &H22 Overlay

Dim T_udp_destport0 As Byte At Packet + &H24 Overlay
Dim T_udp_destport1 As Byte At Packet + &H25 Overlay

Dim T_udp_destport As Word At Packet + &H24 Overlay

Dim T_udp_len0 As Byte At Packet + &H26 Overlay
Dim T_udp_len1 As Byte At Packet + &H27 Overlay
Dim T_udp_chksum0 As Byte At Packet + &H28 Overlay
Dim T_udp_chksum1 As Byte At Packet + &H29 Overlay
Dim T_udp_data As Byte At Packet + &H2A Overlay

Dim T_udp_data1 As Byte At Packet + &H2B Overlay
Dim T_udp_data2 As Byte At Packet + &H2C Overlay
Dim T_udp_data3 As Byte At Packet + &H2D Overlay
Dim T_udp_data4 As Byte At Packet + &H2E Overlay
Dim T_udp_data5 As Byte At Packet + &H2F Overlay
Dim T_udp_data6 As Byte At Packet + &H30 Overlay
Dim T_udp_data7 As Byte At Packet + &H31 Overlay
Dim T_udp_data8 As Byte At Packet + &H32 Overlay
Dim T_udp_data9 As Byte At Packet + &H33 Overlay
Dim T_udp_data10 As Byte At Packet + &H34 Overlay
Dim T_udp_data11 As Byte At Packet + &H35 Overlay
Dim T_udp_data12 As Byte At Packet + &H36 Overlay
Dim T_udp_data13 As Byte At Packet + &H37 Overlay
Dim T_udp_data14 As Byte At Packet + &H38 Overlay
Dim T_udp_data15 As Byte At Packet + &H39 Overlay
Dim T_udp_data16 As Byte At Packet + &H3A Overlay
Dim T_udp_data17 As Byte At Packet + &H3B Overlay
Dim T_udp_data18 As Byte At Packet + &H3C Overlay
Dim T_udp_data19 As Byte At Packet + &H3D Overlay
Dim T_udp_data20 As Byte At Packet + &H3E Overlay
Dim T_udp_data21 As Byte At Packet + &H3F Overlay
Dim T_udp_data22 As Byte At Packet + &H40 Overlay
Dim T_udp_data23 As Byte At Packet + &H41 Overlay
Dim T_udp_data24 As Byte At Packet + &H42 Overlay
Dim T_udp_data25 As Byte At Packet + &H43 Overlay
Dim T_udp_data26 As Byte At Packet + &H44 Overlay
Dim T_udp_data27 As Byte At Packet + &H45 Overlay
Dim T_udp_data28 As Byte At Packet + &H46 Overlay
Dim T_udp_data29 As Byte At Packet + &H47 Overlay
Dim T_udp_data30 As Byte At Packet + &H48 Overlay
Dim T_udp_data31 As Byte At Packet + &H49 Overlay
Dim T_udp_data32 As Byte At Packet + &H4A Overlay

Dim Resend As Byte
Dim Hulp3 As Word
Dim Hulp4 As Byte

Dim Myip(4) As Byte
Dim My_ip As Long At Myip Overlay

Myip(1) = 192
Myip(2) = 168
Myip(3) = 0
Myip(4) = 100

'IP Protocol types
'icmp
Const Prot_icmp = &H01
'tcp
Const Prot_tcp = &H06
'udp
Const Prot_udp = &H11

'NIC_CR page 0/1/2/3 (ps1=x, ps0=x) x = depending on page

'
Const Nic_cr = &H00
'
Const Nic_cr_stp = &B0000_0001                              'stop command - Power up default
Const Nic_cr_sta = &B0000_0010                              'start command
Const Nic_cr_txp = &B0000_0100                              'transmit a packet
Const Nic_cr_rd0 = &B0000_1000                              'remote read
Const Nic_cr_rd1 = &B0001_0000                              'remote write
Const Nic_cr_rd2 = &B0010_0000                              'abort/complete remote DMA
Const Nic_cr_ps0 = &B0100_0000                              'register page 0
Const Nic_cr_ps1 = &B1000_0000                              'register page 1

Const Nic_rdmaport = &H10                                   'all pages
Const Nic_rstport = &H18                                    'all pages


'NIC_PSTART page 0 (ps1=0, ps0=0)
'
Const Nic_pstart = &H01
'

'NIC_PSTOP page 0 (ps1=0, ps0=0)
'
Const Nic_pstop = &H02
'

'NIC_BNRY page 0 (ps1=0, ps0=0)
'
Const Nic_bnry = &H03
'

'NIC_TPSR page 0 (ps1=0, ps0=0)
'
Const Nic_tpsr = &H04
'

'NIC_TBCR0 page 0 (ps1=0, ps0=0)
'
Const Nic_tbcr0 = &H05
'

'NIC_TBCR1 page 0 (ps1=0, ps0=0)
'
Const Nic_tbcr1 = &H06
'

'NIC_ISR page 0 (ps1=0, ps0=0)
'
Const Nic_isr = &H07
'
Const Nic_rdc = &B0100_0000


'NIC_RSAR0 page 0 (ps1=0, ps0=0)
'
Const Nic_rsar0 = &H08
'

'NIC_RSAR1 page 0 (ps1=0, ps0=0)
'
Const Nic_rsar1 = &H09
'

'NIC_rbcr0 page 0 (ps1=0, ps0=0)
'
Const Nic_rbcr0 = &H0A
'

'NIC_rbcr0 page 0 (ps1=0, ps0=0)
'
Const Nic_rbcr1 = &H0B
'

'NIC_rcr page 0 (ps1=0, ps0=0) receive configuration register
'
Const Nic_rcr = &H0C
'

'NIC_tcr page 0 (ps1=0, ps0=0) transmit configuration register
'
Const Nic_tcr = &H0D
'

'NIC_DCR page 0 (ps1=0, ps0=0)
'
Const Nic_dcr = &H0E
'

'NIC_IMR page 0 (ps1=0, ps0=0) interrupt mask register
'
Const Nic_imr = &H0F
'


'NIC_CURR page 1 (ps1=0, ps0=1)
'
Const Nic_curr = &H07
'

'NIC_9346CR page 3 (ps1=1, ps0=1)
'
Const Nic_9346cr = &H01
'
Const Nic_9346cr_eem1 = &B1000_0000
Const Nic_9346cr_eem0 = &B0100_0000
Const Nic_config2_bselb = &B0010_0000


'NIC_CONFIG2 page 3 (ps1=1, ps0=1)
'
Const Nic_config2 = &H05


'NIC_CONFIG3 page 3 (ps1=1, ps0=1)
'
Const Nic_config3 = &H06

Const Msg_initfail = "Init failed"
Const Dcrval = &H58
Const Txstart = &H40
Const Rxstart = &H46
Const Rxstop = &H60
Const Imrval = &H11
Const Tcrval = &H00
Const Rdc = &H40

Declare Sub Write_rtl8019as(byval Regaddr As Byte , Byval Regdata As Byte)
Declare Sub Read_rtl8019as(byval Regaddr As Byte)
Declare Sub Init_rtl8019as
'Declare Sub Showregs
Declare Sub Overrun
Declare Sub Getpacket
Declare Sub Arp_reply
Declare Sub Icmp
Declare Sub Tcp
Declare Sub Udp_receive
Declare Sub Arp
Declare Sub Write_dest_mac


Config Int5 = Falling
Const Debug = 1

#if Debug = 1
Print "Hello world"
#endif

Mymac(1) = &H00
Mymac(2) = &H10
Mymac(3) = &H20
Mymac(4) = &H30
Mymac(5) = &H40
Mymac(6) = &H50

Call Init_rtl8019as
'Call Showregs
'Stop

' Sit and wait for an Interrupt from the RTL8019as

Enable Interrupts
Enable Int5
On Int5 Rtl8019as_interrupt
'start the NIC

Bhulp0 = Nic_cr_rd2 Or Nic_cr_sta
Call Write_rtl8019as(nic_cr , Bhulp0)

Do
Loop


End

' Routine to Write to NIC Control register
'
Sub Write_rtl8019as(regaddr , Regdata)
Whulp0 = Regaddr + &H8300
Out Whulp0 , Regdata
End Sub


' Routine to read from NIC Control register
'
Sub Read_rtl8019as(regaddr)
Whulp0 = Regaddr + &H8300
Byte_read = Inp(whulp0)
End Sub

' Routine to initialize the RTL8019AS ethernetchip
'
Sub Init_rtl8019as
#if Debug = 1
Print "Sub Init_RTL8019as"
#endif
Call Read_rtl8019as(nic_rstport)
Call Write_rtl8019as(nic_rstport , Byte_read)
Waitms 10
'check for good soft reset
Call Write_rtl8019as(nic_imr , 0)                           'interrupt mask register
Call Write_rtl8019as(nic_isr , &HFF)
Call Read_rtl8019as(nic_isr)
'page 0 RST
If Byte_read.7 = 0 Then
Print Msg_initfail
End If

'switch to page 3
Bhulp0 = Nic_cr_rd2 Or Nic_cr_stp
Bhulp0 = Bhulp0 Or Nic_cr_ps0
Bhulp0 = Bhulp0 Or Nic_cr_ps1
Call Write_rtl8019as(nic_cr , Bhulp0)

Bhulp0 = Nic_9346cr_eem0 Or Nic_9346cr_eem1
Call Write_rtl8019as(nic_9346cr , Bhulp0)

Call Write_rtl8019as(nic_config3 , 0)

Call Write_rtl8019as(nic_config2 , Nic_config2_bselb)

Call Write_rtl8019as(nic_9346cr , 0)
Waitms 255

Bhulp0 = Nic_cr_rd2 Or Nic_cr_stp
Call Write_rtl8019as(nic_cr , Bhulp0)
Waitms 2
Call Write_rtl8019as(nic_dcr , Dcrval)                      '58
Call Write_rtl8019as(nic_rbcr0 , &H00)
Call Write_rtl8019as(nic_rbcr1 , &H00)

'0000_0100 packets with broadcast destination address are accepted
Call Write_rtl8019as(nic_rcr , &H04)                        'receive configuration register

Call Write_rtl8019as(nic_tpsr , Txstart)                    '&H40

'0000_0010 internal loopback
Call Write_rtl8019as(nic_tcr , &H02)                        'transmit configuration register

Call Write_rtl8019as(nic_pstart , Rxstart)                  '&H46
Call Write_rtl8019as(nic_bnry , Rxstart)                    '&H46
Call Write_rtl8019as(nic_pstop , Rxstop)
Call Write_rtl8019as(nic_isr , &HFF)

Call Write_rtl8019as(nic_cr , &H61)
Waitms 2
Call Write_rtl8019as(nic_curr , Rxstart)                    '&H46
For Hulp1 = 1 To 6
Call Write_rtl8019as(hulp1 , Mymac(hulp1))
Next Hulp1

Call Write_rtl8019as(nic_cr , &H21)
Call Write_rtl8019as(nic_dcr , Dcrval)                      '58
Call Write_rtl8019as(nic_cr , &H22)
Call Write_rtl8019as(nic_isr , &HFF)

Call Write_rtl8019as(nic_imr , Imrval)                      'interrupt mask register / 0001_0001

Call Write_rtl8019as(nic_tcr , Tcrval)                      'transmit configuration register / 0000_0000

Bhulp0 = Nic_cr_sta Or Nic_cr_rd2
Call Write_rtl8019as(nic_cr , Bhulp0)

End Sub


 'Routine show the contents of the RTL8019as registers

'Sub Showregs
'Local Cntr1 As Byte
'Local Cntr2 As Byte
'Call Write_rtl8019as(nic_cr , &H21)
'Print
'Print "Realtek 8019AS Register dump"
'Print
'Print "REG     Page0   Page1   Page2   Page3"
'Print
'For Cntr1 = 0 To 15
'Cntr2 = Cntr1
'Print Hex(cntr2);
'Print "      ";
'Call Write_rtl8019as(nic_cr , &H21)
'Cntr2 = Cntr1
'Call Read_rtl8019as(cntr2)
'Print Hex(byte_read);
'Print "      ";
'Call Write_rtl8019as(nic_cr , &H61)
'Cntr2 = Cntr1
'Call Read_rtl8019as(cntr2)
'Print Hex(byte_read);
'Print "      ";
'Call Write_rtl8019as(nic_cr , &HA1)
'Cntr2 = Cntr1
'Call Read_rtl8019as(cntr2)
'Print Hex(byte_read);
'Print "      ";
'Call Write_rtl8019as(nic_cr , &HE1)
'Cntr2 = Cntr1
'Call Read_rtl8019as(cntr2)
'Print Hex(byte_read)
'Next Cntr1
'End Sub

' Routine to handle an overrun
'
Sub Overrun
#if Debug = 1
    Print "Sub Overrun"
#endif
Call Read_rtl8019as(nic_cr)
Data_l = Byte_read
Call Write_rtl8019as(nic_cr , &H21)
Waitms 2
Call Write_rtl8019as(nic_rbcr0 , &H00)
Call Write_rtl8019as(nic_rbcr1 , &H00)
Hulp1 = Data_l And &H04
If Hulp1 <> 0 Then
        Resend = 0
    Else
        If Hulp1 = 0 Then
            Call Read_rtl8019as(nic_isr)
            Data_l = Byte_read
            Hulp1 = Data_l And &H02
            Hulp4 = Data_l And &H08
            Hulp3 = Hulp1 Or Hulp4
            If Hulp3 > 0 Then
            Resend = 0
        Else
            Resend = 1
        End If
    End If
End If
Call Write_rtl8019as(nic_tcr , &H02)                        'transmit configuration register

Bhulp0 = Nic_cr_rd2 Or Nic_cr_sta
Call Write_rtl8019as(nic_cr , Bhulp0)

Call Write_rtl8019as(nic_bnry , Rxstart)                    '&H46
Bhulp0 = Nic_cr_ps0 Or Nic_cr_rd2
Bhulp0 = Bhulp0 Or Nic_cr_sta
Call Write_rtl8019as(nic_cr , Bhulp0)

Call Write_rtl8019as(nic_curr , Rxstart)                    '&H46

Bhulp0 = Nic_cr_rd2 Or Nic_cr_sta
Call Write_rtl8019as(nic_cr , Bhulp0)

'0001_0000 OVW
Call Write_rtl8019as(nic_isr , &H10)

Call Write_rtl8019as(nic_tcr , Tcrval)                      'transmit configuration register / 0000_0000
End Sub


' Routine to execute send packet command to retrieve the packet

' Routine to execute send packet command to retrieve the packet
'
Sub Getpacket
#if Debug = 1
     Print "Sub Getpacket"
#endif
Call Write_rtl8019as(nic_cr , &H1A)
For I = 0 To 4
     Call Read_rtl8019as(nic_rdmaport)
     Pageheader(i + 1) = Byte_read
Next I
'watch it. overlay variables
Result16h = T_enetpacketlenh
Result16l = T_enetpacketlenl
Rxlen = Result16
Hulp2 = Rxlen + 1
For I = 1 To Hulp2
     Call Read_rtl8019as(nic_rdmaport)
     'dump any bytes that will overrun the receive buffer
     If I < 1500 Then
          Packet(i + 1) = Byte_read
     End If
Next I
Hulp1 = Byte_read And Nic_rdc
If Hulp1 <> 64 Then
     Call Read_rtl8019as(nic_isr)
End If

Call Write_rtl8019as(nic_isr , &HFF)


' Routine to process an ARP reply/request
'
If T_enetpackettype = &H0608 Then
     If T_arp_hwtype1 = &H01 Then
          If T_arp_prttype1 = &H00 Then
               If T_arp_hwlen = &H06 Then
                    If T_arp_prlen = &H04 Then
                         If My_ip = T_arp_tipaddr Then
                              If T_arp_op1 = &H02 Then
                                   Call Arp_reply
                              End If
                              If T_arp_op1 = &H01 Then
                                   Call Arp
                              End If
                         End If
                    End If
               End If
          End If
     End If
End If


' Routine to go ahead with icmp or udp
'
If T_enetpackettype = &H0008 Then
     If T_ip_destaddr = My_ip Then
          Select Case T_ip_proto
               Case Prot_icmp : Call Icmp
               Case Prot_tcp : Call Tcp
               Case Prot_udp : Call Udp_receive
          End Select
     End If
End If

End Sub


' Routine to handle ARP-traffic
'
Sub Arp
   #if Debug = 1
      Print "Sub Arp"
   #endif
   'Start the NIC
   Call Write_rtl8019as(nic_cr , &H22)
   'load beginning page for transmit buffer
   Call Write_rtl8019as(nic_tpsr , Txstart)                 '&H40
   'set start address for remote DMA operation
   Call Write_rtl8019as(nic_rsar0 , &H00)
   Call Write_rtl8019as(nic_rsar1 , &H40)
   'clear the interrupts
   Call Write_rtl8019as(nic_isr , &HFF)
   'load data byte count for remote DMA
   Call Write_rtl8019as(nic_rbcr0 , &H3C)                   '60 dec
   Call Write_rtl8019as(nic_rbcr1 , &H00)
   'do remote write operation
   Call Write_rtl8019as(nic_cr , &H12)
   'write destination MAC address
   Call Write_dest_mac
   'write source address
   For I = 1 To 6
       Call Write_rtl8019as(nic_rdmaport , Mymac(i))
   Next I
   'arp target IP address
   'arp_op1 = packet(&h16)
   Packet(&H16) = &H02
   For I = 1 To 10
      Hulp1 = &H0C + I
      T = Packet(hulp1)
      Call Write_rtl8019as(nic_rdmaport , T)
   Next I
   'write ethernet module mac address
   For I = 1 To 6
      Call Write_rtl8019as(nic_rdmaport , Mymac(i))
   Next I
   'write myip
   For I = 1 To 4
      Call Write_rtl8019as(nic_rdmaport , Myip(i))
   Next I
   'write remote mac address
   Call Write_dest_mac
   'write remote IP address
   Call Write_rtl8019as(nic_rdmaport , T_arp_sipaddr0)
   Call Write_rtl8019as(nic_rdmaport , T_arp_sipaddr1)
   Call Write_rtl8019as(nic_rdmaport , T_arp_sipaddr2)
   Call Write_rtl8019as(nic_rdmaport , T_arp_sipaddr3)
  'write som pad characters to fill out the packet to the minimum length
   For I = 0 To &H11
      Call Write_rtl8019as(nic_rdmaport , &H00)
   Next I
   'make sure the DMA operation has succesfully completed
   Byte_read = 0
   Do
      Hulp1 = Byte_read And Nic_rdc
      Call Read_rtl8019as(nic_isr)
   Loop Until Hulp1 = 0
   'load numbers of bytes to be transmitted
   Call Write_rtl8019as(nic_tbcr0 , &H3C)
   Call Write_rtl8019as(nic_tbcr1 , &H00)
   'send the contents of the transmit buffer onto the network
   Call Write_rtl8019as(nic_cr , &H24)
End Sub

Sub Arp_reply
#if Debug = 1
    Print "Arp_reply"
#endif
End Sub

Sub Icmp
#if Debug = 1
    Print "ICMP"
#endif
End Sub

Sub Tcp
#if Debug = 1
    Print "TCP"
#endif
End Sub

Sub Udp_receive
#if Debug = 1
    Print "UDP_receive"
#endif
End Sub

' helper-routine
'
Sub Write_dest_mac
   #if Debug = 1
      Print "Sub Write_dest_mac"
   #endif
   Call Write_rtl8019as(nic_rdmaport , T_enetpacketsrc0)
   Call Write_rtl8019as(nic_rdmaport , T_enetpacketsrc1)
   Call Write_rtl8019as(nic_rdmaport , T_enetpacketsrc2)
   Call Write_rtl8019as(nic_rdmaport , T_enetpacketsrc3)
   Call Write_rtl8019as(nic_rdmaport , T_enetpacketsrc4)
   Call Write_rtl8019as(nic_rdmaport , T_enetpacketsrc5)
End Sub



' Routine to handle an interrupt on the RTL8019AS
'
Rtl8019as_interrupt:
   #if Debug = 1
      Print "Interrupt from RTL8019as"
   #endif
   Disable Int5
   'read the interrupt status register
   Call Read_rtl8019as(nic_isr)
   'if the receive buffer has been overrun
   'page 0 - ISR OVW (OVR - receive buffer has been exhausted)
   If Byte_read.4 = 1 Then
      Call Overrun
   End If
   'if the receive buffer holds a good packet
   'page 0 - ISR PRX (PRX - received the packet with no errors)
   If Byte_read.0 = 1 Then
      Call Getpacket
   End If
   'make sure the receive buffer ring is empty. If BNRY = CURR, the buffer is empty
   Call Read_rtl8019as(nic_bnry)
   Data_l = Byte_read

   Bhulp0 = Nic_cr_ps0 Or Nic_cr_rd2
   Bhulp0 = Bhulp0 Or Nic_cr_sta
   'switch to page 1
   Call Write_rtl8019as(nic_cr , Bhulp0)

   Call Read_rtl8019as(nic_curr)
   Data_h = Byte_read

   Bhulp0 = Nic_cr_rd2 Or Nic_cr_sta
   Call Write_rtl8019as(nic_cr , Bhulp0)

   'buffer is not empty, get next packet
   If Data_l <> Data_h Then
      Call Getpacket
   End If

   'reset the interrupts bits
   Call Write_rtl8019as(nic_isr , &HFF)

   Bhulp0 = Nic_cr_rd2 Or Nic_cr_sta
   Call Write_rtl8019as(nic_cr , Bhulp0)
   Enable Int5
Return