© MCS Electronics, 1995-2007
ASM
The routine called is named _serin and is stored in mcs.lib
For the baud rate calculation, _calc_baud is called.
See also
SEROUT
Example
'----------------------------------------------------------------------------- |
|
------------ |
: serin_out.bas |
'name |
'copyright |
: (c) 1995-2005, MCS Electronics |
'purpose |
: demonstration of DYNAMIC software UART |
'micro |
: AT90S2313 |
'suited for demo |
: yes |
'commercial addon needed |
: no |
'-----------------------------------------------------------------------------
------------
$regfile = "2313def.dat" |
' specify the used |
micro |
' used crystal |
$crystal = 4000000 |
frequency |
' use baud rate |
$baud = 19200 |
$hwstack = 32 |
' default use 32 |
for the hardware stack |
' default use 10 |
$swstack = 10 |
for the SW stack |
' default use 40 |
$framesize = 40 |
for the frame space |
|
'tip : Also look at OPEN and CLOSE |
|
'some variables we will use
Dim S As String * 10
Dim Mybaud As Long
'when you pass the baud rate with a variable, make sure you dimesion it as a LONG
Mybaud = 19200 |
|
|
Do |
|
|
|
'first get some data |
|
|
Serin S , 0 , D , 0 , Mybaud , 0 , 8 , 1 |
|
'now send it |
|
|
Serout S , 0 , D , 1 , Mybaud , 0 , 8 , 1 |
|
' |
|
^ 1 stop bit |
' |
|
^---- |
8 data bits |
' |
^ |
^------ |
even parity (0=N, 1 = E, 2=O) |
' |
|
baud rate |
' |
^-------------------- |
|
pin number |
' |
^----------------------- |
|
port so PORTA.0 and PORTA.1 are |
used |
^ |
|
for strings pass 0 |
' |
|
' |
^-------------------------------- |
|
variable |
Wait 1 |
|
|
|
Loop
End
'because the baud rate is passed with a variable in theis example, you could change it under user control
'for example check some DIP switches and change the variable mybaud
© MCS Electronics, 1995-2007
SEROUT
Action
Sends serial data through a dynamic software UART.
Syntax
SEROUT var , bts , port , pin, baud , parity , dbits , sbits
Remarks
While the OPEN and CLOSE statements can be used for software UARTS, they do not permit to use the same pin for input and output. The settings used when opened the communication channel can also not be changed at run time.
The SERIN and SEROUT statements are dynamic software UART routines to performinput and output. You can use them on the same pin for example send some data with SEROUT and get back an answer using SERIN.
Since the SERIN and SEROUT routines can use any pin and can use different parameter values, the code size of these routines is larger.
Parameter |
Description |
Var |
A variable which content is send through the UART. A constant can NOT be |
|
used. |
Bts |
The number of bytes to receive. String variables will wait for a return (ASCII |
|
13). There is no check if the variable you assign is big enough to hold the |
|
result. |
Port |
The name of the port to use. This must be a letter like A for portA. |
Pin |
The pin number you want to use of the port. This must be in the range from |
|
0-7. |
Baud |
The baud rate you want to use. For example 19200. |
Parity |
A number that codes the parity. 0= NONE, 1 = EVEN, 2 = ODD |
Dbits |
The number of data bits. Use 7 or 8. |
Sbits |
The number of stop bits. 1 to 2. |
|
|
The use of SEROUT will create an internal variable named ___SER_BAUD. This is a LONG variable. It is important that you specify the correct crystal value with $CRYSTAL so the correct calculation can be made for the specified baud rate.
Note that ___SER_BAUD will not hold the passed baud rate but will hold the bit delay used internal.
Since the SW UART is dynamic you can change all the params at run time. For example you can store the baud rate in a variable and pass this variable to the SEROUT routine.
Your code could change the baud rate under user controlthis way.
It is important to realize that software timing is used for the bit timing. Any interrupt that occurs during SERIN or SEROUT will delay the transmission. Disable interrupts while you use SERIN or SEROUT.
© MCS Electronics, 1995-2007
The SEROUT will use the pin in Open Collector mode. This means that you can connect several AVR chips and poll the ‘ bus’ with the SERIN statement.
ASM
The routine called is named _serout and is stored in mcs.lib
For the baud rate calculation, _calc_baud is called.
See also
SERIN
Example
'----------------------------------------------------------------------------- |
|
------------ |
: serin_out.bas |
'name |
'copyright |
: (c) 1995-2005, MCS Electronics |
'purpose |
: demonstration of DYNAMIC software UART |
'micro |
: AT90S2313 |
'suited for demo |
: yes |
'commercial addon needed |
: no |
'-----------------------------------------------------------------------------
------------
$regfile = "2313def.dat" |
' specify the used |
micro |
' used crystal |
$crystal = 4000000 |
frequency |
' use baud rate |
$baud = 19200 |
$hwstack = 32 |
' default use 32 |
for the hardware stack |
' default use 10 |
$swstack = 10 |
for the SW stack |
' default use 40 |
$framesize = 40 |
for the frame space |
|
'tip : Also look at OPEN and CLOSE |
|
'some variables we will use
Dim S As String * 10
Dim Mybaud As Long
'when you pass the baud rate with a variable, make sure you dimesion it as a LONG
Mybaud = 19200 |
|
|
Do |
|
|
|
'first get some data |
|
|
Serin S , 0 , D , 0 , Mybaud , 0 , 8 , 1 |
|
'now send it |
|
|
Serout S , 0 , D , 1 , Mybaud , 0 , 8 , 1 |
|
' |
|
^ 1 stop bit |
' |
|
^---- |
8 data bits |
' |
^ |
^------ |
even parity (0=N, 1 = E, 2=O) |
' |
|
baud rate |
' |
^-------------------- |
|
pin number |
' |
^----------------------- |
|
port so PORTA.0 and PORTA.1 are |
used |
^ |
|
for strings pass 0 |
' |
|
' |
^-------------------------------- |
|
variable |
Wait 1 |
|
|
|
© MCS Electronics, 1995-2007
Loop
End
'because the baud rate is passed with a variable in theis example, you could change it under user control
'for example check some DIP switches and change the variable mybaud
SETIPPROTOCOL
Action
Configures socket RAW-mode protocol
Syntax
SETIPPROTOCOL socket, value
Remarks
Socket |
The socket number. (0-3) |
Value |
The IP-protocol value to set. |
|
|
In order to use W3100A’s IPL_RAW Mode, the protocol value of the IP Layer to be used (e.g., 01 in case
of ICMP) needs to be set before socket initialization.
As in UDP, data transmission and reception is possible when the corresponding channel is initialized.
The PING example demonstrates the usage.
As a first step, SETIPPROTOCOL is used :
Setipprotocol Idx , 1
And second, the socket is initialized :
Idx = Getsocket(idx , 3 , 5000 , 0)
The W3100A datasheet does not provide much more details about the IPR register.
See also
SETTCPREGS, GETSOCKET
ASM
NONE
Example
'-----------------------------------------------------------------------------------------
'name |
: PING_TWI.bas |
http://www.faqs.org/rfcs/rfc792.html |
'copyright |
: (c) 1995-2005, MCS Electronics |
'purpose |
: Simple PING program |
|
'micro |
:Mega88 |
|
'suited for demo |
: yes |
|
'commercial addon needed : no |
|
'----------------------------------------------------------------------------------------- |
|
' specify the used micro |
$regfile= "m32def.dat" |
