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DHCP.spin
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DHCP.spin
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'' DHCP Version 1.0
'' Copyright (c) 2010 Roy ELtham
'' November 15, 2010
'' See end of file for terms of use
''
'' This is an implementation of DHCP for the Spinneret Web Server.
''
CON
_clkmode = xtal1 + pll16x
_xinfreq = 5_000_000
'W5100 Interface
W5100_DATA0 = 0
W5100_DATA1 = 1
W5100_DATA2 = 2
W5100_DATA3 = 3
W5100_DATA4 = 4
W5100_DATA5 = 5
W5100_DATA6 = 6
W5100_DATA7 = 7
W5100_ADDR0 = 8
W5100_ADDR1 = 9
W5100_WR = 10
W5100_RD = 11
W5100_CS = 12
W5100_INT = 13
W5100_RST = 14
W5100_SEN = 15
' UDP port numbers for DHCP
DHCP_SERVER_PORT = 67 ' from server to client
DHCP_CLIENT_PORT = 68 ' from client to server
' DHCP message OP code
DHCP_BOOTREQUEST = 1
DHCP_BOOTREPLY = 2
' DHCP message type
DHCP_DISCOVER = 1
DHCP_OFFER = 2
DHCP_REQUEST = 3
DHCP_DECLINE = 4
DHCP_ACK = 5
DHCP_NAK = 6
DHCP_RELEASE = 7
DHCP_INFORM = 8
' MISC DHCP stuff
DHCP_TIMEOUT = 80_000_000 * 4 ' 4 seconds, assumes 80Mhz clkfreq
DHCP_FLAGSBROADCAST = $8000
DHCP_HTYPE10MB = 1
DHCP_HLENETHERNET = 6
MAGIC_COOKIE_0 = $63
MAGIC_COOKIE_1 = $82
MAGIC_COOKIE_2 = $53
MAGIC_COOKIE_3 = $63
' DHCP Options
OPT_padOption = 0
OPT_subnetMask = 1
OPT_timerOffset = 2
OPT_routersOnSubnet = 3
OPT_timeServer = 4
OPT_nameServer = 5
OPT_dns = 6
OPT_logServer = 7
OPT_cookieServer = 8
OPT_lprServer = 9
OPT_impressServer = 10
OPT_resourceLocationServer = 11
OPT_hostName = 12
OPT_bootFileSize = 13
OPT_meritDumpFile = 14
OPT_domainName = 15
OPT_swapServer = 16
OPT_rootPath = 17
OPT_extentionsPath = 18
OPT_IPforwarding = 19
OPT_nonLocalSourceRouting = 20
OPT_policyFilter = 21
OPT_maxDgramReasmSize = 22
OPT_defaultIPTTL = 23
OPT_pathMTUagingTimeout = 24
OPT_pathMTUplateauTable = 25
OPT_ifMTU = 26
OPT_allSubnetsLocal = 27
OPT_broadcastAddr = 28
OPT_performMaskDiscovery = 29
OPT_maskSupplier = 30
OPT_performRouterDiscovery = 31
OPT_routerSolicitationAddr = 32
OPT_staticRoute = 33
OPT_trailerEncapsulation = 34
OPT_arpCacheTimeout = 35
OPT_ethernetEncapsulation = 36
OPT_tcpDefaultTTL = 37
OPT_tcpKeepaliveInterval = 38
OPT_tcpKeepaliveGarbage = 39
OPT_nisDomainName = 40
OPT_nisServers = 41
OPT_ntpServers = 42
OPT_vendorSpecificInfo = 43
OPT_netBIOSnameServer = 44
OPT_netBIOSdgramDistServer = 45
OPT_netBIOSnodeType = 46
OPT_netBIOSscope = 47
OPT_xFontServer = 48
OPT_xDisplayManager = 49
OPT_dhcpRequestedIPaddr = 50
OPT_dhcpIPaddrLeaseTime = 51
OPT_dhcpOptionOverload = 52
OPT_dhcpMessageType = 53
OPT_dhcpServerIdentifier = 54
OPT_dhcpParamRequest = 55
OPT_dhcpMsg = 56
OPT_dhcpMaxMsgSize = 57
OPT_dhcpT1value = 58
OPT_dhcpT2value = 59
OPT_dhcpClassIdentifier = 60
OPT_dhcpClientIdentifier = 61
OPT_endOption = 255
' offsets for UDP header
UDP_HEADER_DESTADDR = 0
UDP_HEADER_PORT = 4
UDP_HEADER_PAYLOADSIZE = 6
UDP_HEADER_SIZE = 8
' offsets for DHCP packet (UDP header is in front of this)
DHCP_OP = 8
DHCP_HTYPE = 9
DHCP_HLEN = 10
DHCP_HOPS = 11
DHCP_XID = 12
DHCP_SECS = 16
DHCP_FLAGS = 18
DHCP_CIADDR = 20
DHCP_YIADDR = 24
DHCP_SIADDR = 28
DHCP_GIADDR = 32
DHCP_CHADDR = 36
DHCP_SNAME = 52
DHCP_FILE = 116
DHCP_COOKIE = 244
DHCP_OPT = 248
DHCP_END = 556
' return codes
SUCCESS = 0
SOCKET_FAILED_OPENING = 1
SERVER_TIMEOUT = 2
SERVER_NAK = 3
BUFFER_SIZE = 2048
VAR
byte MAC_Address[6]
byte IP[4]
byte SubnetMask[4]
byte GatewayIP[4]
long DHCP_LeaseTime ' duration of lease in seconds
byte DHCP_Server[4]
byte DNS_Server[4]
byte HostName[64]
byte DomainName[64] ' you may need to make this larger if you have a very long domain name
byte Buffer[BUFFER_SIZE]
DAT
DEFAULT_HOST_NAME BYTE "Spinneret", 0
OBJ
W5100 : "Brilldea_W5100_Indirect_Driver_Ver006.spin"
{
PST : "Parallax Serial Terminal"
PUB main
PST.Start(115200)
' sets up W5100 and initializes our variables
Start
MAC_Address[0] := $00
MAC_Address[1] := $00
MAC_Address[2] := $00
MAC_Address[3] := $00
MAC_Address[4] := $00
MAC_Address[5] := $00
W5100.WriteMACaddress(true, @MAC_Address[0])
' delay to allow time to enable PST
PauseMSec(2000)
PST.Home
PST.Clear
PST.Str(string("DHCP Demo", PST#NL, PST#NL))
result := DoDHCP(0, $4242_4242)
' at this point if result == SUCCESS, then the W5100 is configured
if result == SUCCESS
PST.Str(string("IP : "))
PST.Dec(IP[0])
PST.Str(string("."))
PST.Dec(IP[1])
PST.Str(string("."))
PST.Dec(IP[2])
PST.Str(string("."))
PST.Dec(IP[3])
PST.Str(string(PST#NL))
PST.Str(string("Subnet Mask: "))
PST.Dec(SubnetMask[0])
PST.Str(string("."))
PST.Dec(SubnetMask[1])
PST.Str(string("."))
PST.Dec(SubnetMask[2])
PST.Str(string("."))
PST.Dec(SubnetMask[3])
PST.Str(string(PST#NL))
PST.Str(string("Gateway IP : "))
PST.Dec(GatewayIP[0])
PST.Str(string("."))
PST.Dec(GatewayIP[1])
PST.Str(string("."))
PST.Dec(GatewayIP[2])
PST.Str(string("."))
PST.Dec(GatewayIP[3])
PST.Str(string(PST#NL))
PST.Str(string("DNS Server : "))
PST.Dec(DNS_Server[0])
PST.Str(string("."))
PST.Dec(DNS_Server[1])
PST.Str(string("."))
PST.Dec(DNS_Server[2])
PST.Str(string("."))
PST.Dec(DNS_Server[3])
PST.Str(string(PST#NL))
PST.Str(string("DHCP Server: "))
PST.Dec(DHCP_Server[0])
PST.Str(string("."))
PST.Dec(DHCP_Server[1])
PST.Str(string("."))
PST.Dec(DHCP_Server[2])
PST.Str(string("."))
PST.Dec(DHCP_Server[3])
PST.Str(string(PST#NL))
PST.Str(string("Domain Name: "))
PST.Str(@DomainName)
PST.Str(string(PST#NL))
else
PST.Str(string("Error: "))
PST.Dec(result)
PST.Str(string(PST#NL))
Stop
'}
PUB Start
' clear all our variables
BYTEFILL(@MAC_Address[0], 0, 158)
' set the default host name
BYTEMOVE(@HostName[0], @DEFAULT_HOST_NAME[0], STRSIZE(@DEFAULT_HOST_NAME[0]))
' init the Wiznet 5100 chip
W5100.StartINDIRECT(W5100_DATA0, W5100_ADDR0, W5100_ADDR1, W5100_CS, W5100_RD, W5100_WR, W5100_RST, W5100_SEN)
PUB Stop
W5100.StopINDIRECT
'' only call these GetXXX functions after calling DoDHCP()
PUB GetIP(ipPtr)
bytemove(ipPtr, @IP[0], 4)
PUB GetGatewayIP(gatewayPtr)
bytemove(gatewayPtr, @GatewayIP[0], 4)
PUB GetSubnetMask(subnetPtr)
bytemove(subnetPtr, @SubnetMask[0], 4)
PUB GetDNSServer(dnsPtr)
bytemove(dnsPtr, @DNS_Server[0], 4)
PUB GetDHCPServer(dhcpPtr)
bytemove(dhcpPtr, @DHCP_Server[0], 4)
PUB GetDomainName
return @DomainName[0]
PUB GetLeaseTime
return DHCP_LeaseTime
'' call this function after Start, but before DoDHCP()
PUB SetHostName(newHostName)
bytemove(@HostName[0], newHostName, STRSIZE(newHostName))
PUB GetHostName
return @HostName[0]
'' call this function after Start, but before DoDHCP()
PUB SetMAC_Address(newMAC_Address)
MAC_Address[0] := byte[newMAC_Address][0]
MAC_Address[1] := byte[newMAC_Address][1]
MAC_Address[2] := byte[newMAC_Address][2]
MAC_Address[3] := byte[newMAC_Address][3]
MAC_Address[4] := byte[newMAC_Address][4]
MAC_Address[5] := byte[newMAC_Address][5]
W5100.WriteMACaddress(true, @MAC_Address[0])
PUB GetMAC_Address(macPtr)
bytemove(macPtr, @MAC_Address[0], 6)
'' You should call SetMAC_Address() and SetHostName() before calling this.
PUB DoDHCP(socket, XID) | packetSize, startCnt, timeoutCnt, currentCnt, serverReply, DestinationIP[4], status
' open the socket with the broadcast IP and the DHCP port
DestinationIP[0] := 255
DestinationIP[1] := 255
DestinationIP[2] := 255
DestinationIP[3] := 255
W5100.SocketOpen(socket, W5100#_UDPPROTO, DHCP_CLIENT_PORT, DHCP_CLIENT_PORT, @DestinationIP[0])
' check the status of the socket
status := ReadStatus(socket)
if status <> W5100#_SOCK_UDP
return SOCKET_FAILED_OPENING
' construct a DHCP Discover packet and send it, this asks DHCP servers to send us an Offer packet
FillHeader(255,255,255,255, 67, DHCP_END-UDP_HEADER_SIZE, @Buffer[0])
FillDiscoverPacket(XID, @Buffer[0])
W5100.txUDP(socket, @Buffer[0])
PauseMSec(100)
' wait for a DHCP Offer reply, we just go with the first server to reply
startCnt := CNT
timeoutCnt := startCnt + DHCP_TIMEOUT
repeat
packetSize := W5100.rxUDP(socket, @Buffer[0])
if packetSize > 0
serverReply := ParseDHCPReply(XID, DHCP_OFFER, @Buffer[0])
case serverReply
1: ' we got our packet
QUIT
2: ' got NAK from server
W5100.SocketClose(socket)
return SERVER_NAK
' check for timeout, handling wrap case
currentCnt := CNT
if startCnt < timeoutCnt
if (currentCnt => timeoutCnt) OR (currentCnt < startCnt)
return SERVER_TIMEOUT
else
if (currentCnt => timeoutCnt) AND (currentCnt < startCnt)
return SERVER_TIMEOUT
' construct a DHCP Request packet and send it, requesting to claim the offered IP
FillHeader(255,255,255,255, 67, DHCP_END-UDP_HEADER_SIZE, @Buffer[0])
FillRequestPacket(XID, @Buffer[0])
W5100.txUDP(socket, @Buffer[0])
PauseMSec(100)
' wait for a DHCP Ack reply, this grants us our claim on the IP
startCnt := CNT
timeoutCnt := startCnt + DHCP_TIMEOUT
repeat
packetSize := W5100.rxUDP(socket, @Buffer[0])
if packetSize > 0
serverReply := ParseDHCPReply(XID, DHCP_ACK, @Buffer[0])
case serverReply
1: ' we got our packet
QUIT
2: ' got NAK from server
W5100.SocketClose(socket)
return SERVER_NAK
' check for timeout, handling wrap case
currentCnt := CNT
if startCnt < timeoutCnt
if (currentCnt => timeoutCnt) OR (currentCnt < startCnt)
return SERVER_TIMEOUT
else
if (currentCnt => timeoutCnt) AND (currentCnt < startCnt)
return SERVER_TIMEOUT
W5100.WriteGatewayAddress(true, @GatewayIP[0])
W5100.WriteSubnetMask(true, @SubnetMask[0])
W5100.WriteIPAddress(true, @IP[0])
W5100.SocketClose(socket)
return SUCCESS
PUB RenewLease(socket)
'still to be done
return SERVER_NAK
PRI ReadStatus(socket) | socketStatus
W5100.readIND((W5100#_S0_SR + (socket * $0100)), @socketStatus, 1)
{
case socketStatus
W5100#_SOCK_CLOSED : PST.Str(string("$00 - socket closed", PST#NL, PST#NL))
W5100#_SOCK_INIT : PST.Str(string("$13 - socket initalized", PST#NL, PST#NL))
W5100#_SOCK_LISTEN : PST.Str(string("$14 - socket listening", PST#NL, PST#NL))
W5100#_SOCK_ESTAB : PST.Str(string("$17 - socket established", PST#NL, PST#NL))
W5100#_SOCK_UDP : PST.Str(string("$22 - socket UDP open", PST#NL, PST#NL))
'}
return socketStatus
PRI FillHeader(ip0,ip1,ip2,ip3, port, payloadSize, packetBuffer)
byte[packetBuffer][UDP_HEADER_DESTADDR] := ip3
byte[packetBuffer][UDP_HEADER_DESTADDR+1] := ip2
byte[packetBuffer][UDP_HEADER_DESTADDR+2] := ip1
byte[packetBuffer][UDP_HEADER_DESTADDR+3] := ip0
byte[packetBuffer][UDP_HEADER_PORT] := port.byte[1]
byte[packetBuffer][UDP_HEADER_PORT+1] := port.byte[0]
byte[packetBuffer][UDP_HEADER_PAYLOADSIZE] := payloadSize.byte[1]
byte[packetBuffer][UDP_HEADER_PAYLOADSIZE+1] := payloadSize.byte[0]
PRI FillBasePacket(XID, messageType, packetBuffer) | index, optionOffset, hostNameLength
BYTEFILL(@byte[packetBuffer][DHCP_OP], 0, DHCP_END-UDP_HEADER_SIZE)
byte[packetBuffer][DHCP_OP] := DHCP_BOOTREQUEST
byte[packetBuffer][DHCP_HTYPE] := DHCP_HTYPE10MB
byte[packetBuffer][DHCP_HLEN] := DHCP_HLENETHERNET
byte[packetBuffer][DHCP_XID+0] := XID.byte[3]
byte[packetBuffer][DHCP_XID+1] := XID.byte[2]
byte[packetBuffer][DHCP_XID+2] := XID.byte[1]
byte[packetBuffer][DHCP_XID+3] := XID.byte[0]
word[@byte[packetBuffer][DHCP_FLAGS]] := ByteSwapWord(DHCP_FLAGSBROADCAST)
repeat index from 0 to 5
byte[packetBuffer][DHCP_CHADDR+index] := MAC_Address[index]
byte[packetBuffer][DHCP_COOKIE+0] := MAGIC_COOKIE_0
byte[packetBuffer][DHCP_COOKIE+1] := MAGIC_COOKIE_1
byte[packetBuffer][DHCP_COOKIE+2] := MAGIC_COOKIE_2
byte[packetBuffer][DHCP_COOKIE+3] := MAGIC_COOKIE_3
optionOffset := 0
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_dhcpMessageType
byte[packetBuffer][DHCP_OPT+optionOffset++] := 1
byte[packetBuffer][DHCP_OPT+optionOffset++] := messageType
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_dhcpClientIdentifier
byte[packetBuffer][DHCP_OPT+optionOffset++] := 7
byte[packetBuffer][DHCP_OPT+optionOffset++] := 1
repeat index from 0 to 5
byte[packetBuffer][DHCP_OPT+optionOffset++] := MAC_Address[index]
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_hostName
hostNameLength := STRSIZE(@HostName[0])
' force to be even, so next option after this will be word aligned (16bit)
if (hostNameLength & 1) == 1
hostNameLength += 1
byte[packetBuffer][DHCP_OPT+optionOffset++] := hostNameLength
repeat index from 0 to hostNameLength-1
byte[packetBuffer][DHCP_OPT+optionOffset++] := HostName[index]
return optionOffset
PRI FillDiscoverPacket(XID, packetBuffer) | optionOffset
optionOffset := FillBasePacket(XID, DHCP_DISCOVER, packetBuffer)
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_dhcpParamRequest
byte[packetBuffer][DHCP_OPT+optionOffset++] := 6
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_subnetMask
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_domainName
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_dns
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_routersOnSubnet
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_dhcpT1value
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_dhcpT2value
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_endOption
PRI FillRequestPacket(XID, packetBuffer) | optionOffset
optionOffset := FillBasePacket(XID, DHCP_REQUEST, packetBuffer)
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_dhcpRequestedIPaddr
byte[packetBuffer][DHCP_OPT+optionOffset++] := 4
byte[packetBuffer][DHCP_OPT+optionOffset++] := IP[0]
byte[packetBuffer][DHCP_OPT+optionOffset++] := IP[1]
byte[packetBuffer][DHCP_OPT+optionOffset++] := IP[2]
byte[packetBuffer][DHCP_OPT+optionOffset++] := IP[3]
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_dhcpServerIdentifier
byte[packetBuffer][DHCP_OPT+optionOffset++] := 4
byte[packetBuffer][DHCP_OPT+optionOffset++] := DHCP_Server[0]
byte[packetBuffer][DHCP_OPT+optionOffset++] := DHCP_Server[1]
byte[packetBuffer][DHCP_OPT+optionOffset++] := DHCP_Server[2]
byte[packetBuffer][DHCP_OPT+optionOffset++] := DHCP_Server[3]
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_dhcpParamRequest
byte[packetBuffer][DHCP_OPT+optionOffset++] := 8
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_subnetMask
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_routersOnSubnet
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_dns
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_domainName
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_dhcpT1value
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_dhcpT2value
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_performRouterDiscovery
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_staticRoute
byte[packetBuffer][DHCP_OPT+optionOffset++] := OPT_endOption
PRI ParseDHCPReply(XID, expectedType, packetBuffer) | index, optionOffset, option, optionLength, port, payloadSize
port := ByteSwapWord(word[@byte[packetBuffer][UDP_HEADER_PORT]])
payloadSize := ByteSwapWord(word[@byte[packetBuffer][UDP_HEADER_PAYLOADSIZE]])
' verify the packet is from the DHCP server and is at least of minimum size
if port <> DHCP_SERVER_PORT OR payloadSize < DHCP_OPT
return 0 ' this is not a DHCP packet
' verify that the packet is a DHCP Reply
if byte[packetBuffer][DHCP_OP] <> DHCP_BOOTREPLY
return 0 ' this is not a DHCP Reply
' verify XID match
repeat index from 0 to 3
if XID.byte[index] <> byte[packetBuffer][DHCP_XID+3-index]
return 0 ' does not match, so not for us
' verify MAC Address match
repeat index from 0 to 5
if MAC_Address[index] <> byte[packetBuffer][DHCP_CHADDR+index]
return 0 ' does not match, so not for us
' save the IP that is offered/claimed
IP[0] := byte[packetBuffer][DHCP_YIADDR+0]
IP[1] := byte[packetBuffer][DHCP_YIADDR+1]
IP[2] := byte[packetBuffer][DHCP_YIADDR+2]
IP[3] := byte[packetBuffer][DHCP_YIADDR+3]
DHCP_LeaseTime := 0
' scan through options pulling out stuff we need
optionOffset := 0
repeat
option := byte[packetBuffer][DHCP_OPT+optionOffset++]
if option <> 0
optionLength := byte[packetBuffer][DHCP_OPT+optionOffset++]
else
optionLength := 0
case option
OPT_endOption :
QUIT
OPT_dhcpMessageType :
if byte[packetBuffer][DHCP_OPT+optionOffset] <> expectedType
if byte[packetBuffer][DHCP_OPT+optionOffset] == DHCP_NAK
return 2
else
return 0
OPT_subnetMask :
SubnetMask[0] := byte[packetBuffer][DHCP_OPT+optionOffset+0]
SubnetMask[1] := byte[packetBuffer][DHCP_OPT+optionOffset+1]
SubnetMask[2] := byte[packetBuffer][DHCP_OPT+optionOffset+2]
SubnetMask[3] := byte[packetBuffer][DHCP_OPT+optionOffset+3]
OPT_routersOnSubnet :
GatewayIP[0] := byte[packetBuffer][DHCP_OPT+optionOffset+0]
GatewayIP[1] := byte[packetBuffer][DHCP_OPT+optionOffset+1]
GatewayIP[2] := byte[packetBuffer][DHCP_OPT+optionOffset+2]
GatewayIP[3] := byte[packetBuffer][DHCP_OPT+optionOffset+3]
OPT_dhcpIPaddrLeaseTime :
DHCP_LeaseTime.byte[0] := byte[packetBuffer][DHCP_OPT+optionOffset+3]
DHCP_LeaseTime.byte[1] := byte[packetBuffer][DHCP_OPT+optionOffset+2]
DHCP_LeaseTime.byte[2] := byte[packetBuffer][DHCP_OPT+optionOffset+1]
DHCP_LeaseTime.byte[3] := byte[packetBuffer][DHCP_OPT+optionOffset+0]
OPT_dns :
DNS_Server[0] := byte[packetBuffer][DHCP_OPT+optionOffset+0]
DNS_Server[1] := byte[packetBuffer][DHCP_OPT+optionOffset+1]
DNS_Server[2] := byte[packetBuffer][DHCP_OPT+optionOffset+2]
DNS_Server[3] := byte[packetBuffer][DHCP_OPT+optionOffset+3]
OPT_dhcpServerIdentifier :
DHCP_Server[0] := byte[packetBuffer][DHCP_OPT+optionOffset+0]
DHCP_Server[1] := byte[packetBuffer][DHCP_OPT+optionOffset+1]
DHCP_Server[2] := byte[packetBuffer][DHCP_OPT+optionOffset+2]
DHCP_Server[3] := byte[packetBuffer][DHCP_OPT+optionOffset+3]
OPT_domainName :
BYTEMOVE(@DomainName[0], @byte[packetBuffer][DHCP_OPT+optionOffset], optionLength)
optionOffset += optionLength
return 1
PRI ByteSwapWord(value)
result.byte[0] := value.byte[1]
result.byte[1] := value.byte[0]
PRI PauseMSec(Duration)
'' Pause execution for specified milliseconds.
'' This routine is based on the set clock frequency.
''
'' params: Duration = number of milliseconds to delay
'' return: none
waitcnt(((clkfreq / 1_000 * Duration - 3932) #> 381) + cnt)
{{
┌──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ TERMS OF USE: MIT License │
├──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation │
│files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, │
│modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software│
│is furnished to do so, subject to the following conditions: │
│ │
│The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.│
│ │
│THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE │
│WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR │
│COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, │
│ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │
└──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
}}