Software Crestron SIMPL+
®
100 z SIMPL+
®
Language Reference Guide - DOC. 5797G
Bit & Byte Functions
Bit & Byte Functions Overview
These functions perform bit and byte masking operations in a given SIMPL+
program.
Bit
Name:
Bit
Syntax:
INTEGER Bit(STRING SOURCE, INTEGER SOURCE_BYTE, INTEGER
BIT_IN_BYTE);
Description:
Determine the state of a specified bit in a particular byte of a given string.
Parameters:
SOURCE contains a STRING in which a bit of one byte is to be examined. Each
character in SOURCE is considered one byte.
SOURCE_BYTE references a character in the SOURCE string. The leftmost
character in SOURCE is considered 1.
BIT_IN_BYTE specifies which bit in the SOURCE_BYTE of SOURCE is to be
examined. BIT_IN_BYTE starts at position 0 (least significant or rightmost bit of the
byte). 7 is the most significant or leftmost bit of the byte.
Return Value:
Returns 0 or 1 for a valid bit position. Illegal bit references will return 65535. It is
illegal if SOURCE_BYTE is 0 or greater than the length of the SOURCE string. Note
that it is legal to specify a bit beyond 7. This will reference a bit in another byte. In
this way, a source string can be used as a set of packed bit flags. The algorithm for
determining which bit in which byte is set when BIT_IN_BYTE is greater than 7 is
as follows:
Actual Byte in SOURCE = (BIT_IN_BYTE / 8) + SOURCE_BYTE
Actual Bit in Actual Byte = (BIT_IN_BYTE MOD 8)
Applying this to BIT (“abc”,1,16) will reference bit 0 of byte 3 (the least significant
bit of byte “c” in SOURCE).
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