view docs/ccguide/crc.refentry @ 2798:b70d93f8d7ce lwtools-port

Updated coco1/modules/makefile and coco3/modules/makefile to help resolve issues with i(x) and s(x) descriptors. Updated level1/coco1/modules/makefile & level2/coco3/modules/makefile so that correct values would be sent to assembler when building superdesc.asm for s(x).dd and i(x).dd descriptors.
author drencor-xeen
date Mon, 28 Jan 2013 16:13:05 -0600
parents c0da1728ed5b
children
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<refentry id="crc">
<refnamediv>
<refname>Crc</refname>
<refpurpose>compute a cyclic redundancy count</refpurpose>
</refnamediv>

<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
  <funcdef><function>crc</function></funcdef>
  <paramdef>char *<parameter>start</parameter></paramdef>
  <paramdef>int <parameter>count</parameter></paramdef>
  <paramdef>char <parameter>accum</parameter>[3]</paramdef>
</funcprototype>
</funcsynopsis>

</refsynopsisdiv>

<refsect1><title>Assembler Equivalent</title>
<para>
os9 F$CRC
</para>
</refsect1>

<refsect1><title>Description</title>
<para>
This call accumulates a crc into a three byte array at "accum"
for "count" bytes starting at "start". All three bytes of
"accum" should be initialized to 0xff before the first call to
"crc()". However, repeated calls can be subsequently made to
cover an entire module. If the result is to be used as an OS-9
module crc, it should have its bytes complemented before
insertion at the end of the module.
</para>
</refsect1>
</refentry>