Файл: BASCOM AVR, help reference (2007).pdf

© MCS Electronics, 1995-2007

Remarks

Value A constant that fits into a LONG , indicating how much time must be waited before the waiting is terminated.

All RS-232 serial statements and functions(except INKEY) that use the HW UART, will halt the program until a character is received. Only with buffered serial input you can process your main program while the buffer received data on the background.

$TIMEOUT is an alternative for normal serial reception. It is not intended to be used with buffered serial reception.

When you assign a constant to $TIMEOUT, you actual assign a value to the internal created value named ___TIMEOUT.

This value will be decremented in the routine that waits for serial data. When it reaches zero, it will terminate.

So the bigger the value, the longer the wait time before the timeout occurs. The timeout is not in seconds or microseconds, it is a relative number. Only the speed of the oscillator has effect on the duration. And the value of the number of course.

When the time out is reached, a zero/null will be returned to the calling routine. Waitkey() will return 0 when used with a byte. When you use INPUT with a string, the timeout will be set for every character. So when 5 characters are expected, and they arrive just before the timeout value is reached, it may take a long time until the code is executed.

When the timeout occurs on the first character, it will return much faster.

When you already sent data, this data will be returned. For example, "123" was sent but a RETURN was never sent, INPUT will return "123". While without the $TIMEOUT, INPUT will not return until a RETURN is received.

When you activate $TIMEOUT, and your micro has two UARTS(Mega128 for example) it will be active for both UART0 and UART1.

See Also

INPUT , WAITKEY

Example

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'most serial communication functions and routines wait until a character 'or end of line is received.

'This blocks execution of your program. SOmething you can change by using buffered input

'There is also another option : using a timeout '$timeout Does Not Work With Buffered Serial Input

Dim Sname As String * 10

Dim B As Byte

Do

$timeout = 1000000

Input "Name : " , Sname

Print "Hello " ; Sname

$timeout = 5000000

Input "Name : " , Sname Print "Hello " ; Sname

Loop

'you can re-configure $timeout

$TINY

Action

Instruct the compiler to generate initialize code without setting up the stacks.

Syntax

$TINY

Remarks

The tiny11 for example is a powerful chip. It only does not have SRAM. BASCOM depends on SRAM for the hardware stack and software stack.

When you like to program in ASM you can use BASCOM with the $TINY directive.

Some BASCOM statements will also already work but the biggest part wil not work.

A future version will support a subset of the BASCOM statements and function to be used with the chips without SRAM.

Note that the generated code is not yet optimized for the tiny parts. Some used ASM statements for example will not work because the chip does not support it.

See also

NONE

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© MCS Electronics, 1995-2007

ASM

NONE

Example

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$WAITSTATE

Action

Compiler directive to activate external SRAM and to insert a WAIT STATE for a slower ALE signal.

CONFIG XRAM should be used instead.

Syntax

$WAITSTATE

Remarks

The $WAITSTATE can be used to override the Compiler Chip Options setting.

Wait states are needed for slow external components that can not handle the fast ALE signal from the AVR chip.

See also

$XA , CONFIG XRAM

Example

$WAITSTATE

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1WIRECOUNT

Action

This statement reads the number of 1wire devices attached to the bus.

Syntax

var2 = 1WIRECOUNT()

var2 = 1WIRECOUNT( port , pin)

Remarks

The variable must be of the type word or integer.

You can use the 1wirecount() function to know how many times the 1wsearchNext() function should be called to get all the Id's on the bus.

The 1wirecount function will take 4 bytes of SRAM.

___1w_bitstorage , Byte used for bit storage : lastdeviceflag bit 0

id_bit bit 1 cmp_id_bit bit 2 search_dir bit 3

___1wid_bit_number, Byte

___1wlast_zero, Byte

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© MCS Electronics, 1995-2007

___1wlast_discrepancy , Byte

ASM

The following asm routines are called from mcs.lib.

_1wire_Count : (calls _1WIRE, _1WIRE_SEARCH_FIRST , _1WIRE_SEARCH_NEXT)

Parameters passed : R24 : pin number, R30 : port , Y+0,Y+1 : 2 bytes of soft stack, X : pointer to the frame space

Returns Y+0 and Y+1 with the value of the count. This is assigned to the target variable.

See also

1WWRITE , 1WRESET , 1WREAD , 1WSEARCHFIRST, 1WSEARCHNEXT , Using the 1wire protocol

Example

'The following internal bytes are used by the scan routines '___1w_bitstorage , Byte used for bit storage :

'lastdeviceflag bit 0

'[DIM variables used]

'we need some space from at least 8 bytes to store the ID

Dim Reg_no(8) As Byte

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